U.S. patent application number 09/810440 was filed with the patent office on 2001-11-29 for linear copolymers of alpha-olefins and divinylbenzene having narrow molecular weight and composition distributions, graft copolymers derived therefrom, and process for preparing same.
Invention is credited to Chung, Tze-Chiang, Dong, Jin Yong.
Application Number | 20010047069 09/810440 |
Document ID | / |
Family ID | 27000442 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010047069 |
Kind Code |
A1 |
Chung, Tze-Chiang ; et
al. |
November 29, 2001 |
Linear copolymers of alpha-olefins and divinylbenzene having narrow
molecular weight and composition distributions, graft copolymers
derived therefrom, and process for preparing same
Abstract
The invention relates to polyolefin copolymers (I) 1 and to
graft copolymers (II) 2 which are prepared from the copolymers (I),
wherein the copolymers (I) are linear copolymers containing
divinylbenzene comonomer units selected from the group consisting
of 1,4-divinylbenzene units, mixtures of 1,4- and
1,3-divinylbenzene units and mixtures of 1,4-, 1,3- and
1,2-divinylbenzene units, wherein R, in formulas I and II, is a
C.sub.1 to C.sub.10 linear or branched alkyl group or a C.sub.6 to
C.sub.10 substituted or unsubstituted aromatic group; and wherein G
and G', independently, are selected from --H, --OH, epoxy,
--NH.sub.2, --COOH, anhydride, --Cl, --Br, --M, --COOM (M=metal) or
a polymer chain having the molecular weight of at least about 500,
which can be derived from both step and chain polymerization
reactions. In the graft copolymer (II), the combined alpha-olefin
mole % (x+y) is from about 50 and 99.9 mole %, the sum of x, y, m
and n is 100%, n is at least 0.05%, and the backbone polymer chain
has a number average molecular weight (Mn) of at least about
1,000.
Inventors: |
Chung, Tze-Chiang; (State
College, PA) ; Dong, Jin Yong; (State College,
PA) |
Correspondence
Address: |
Anthony J. De Laurentis
2001 Jefferson Davis Highway, Suite 200
Arlington
VA
22202
US
|
Family ID: |
27000442 |
Appl. No.: |
09/810440 |
Filed: |
March 19, 2001 |
Related U.S. Patent Documents
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Application
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Filing Date |
Patent Number |
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09810440 |
Mar 19, 2001 |
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09359345 |
Jul 21, 1999 |
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6096849 |
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09359345 |
Jul 21, 1999 |
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09573737 |
May 18, 2000 |
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6265493 |
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Current U.S.
Class: |
526/336 ;
525/105; 525/250; 525/259; 525/285; 526/126; 526/127; 526/134;
526/160; 526/170; 526/348.2; 526/943 |
Current CPC
Class: |
C08F 210/06 20130101;
C08F 210/06 20130101; Y02P 20/582 20151101; C08F 4/65925 20130101;
C08F 210/16 20130101; C08F 210/18 20130101; C08F 4/6592 20130101;
C08F 210/18 20130101; C08F 210/16 20130101; C08F 210/02 20130101;
C08F 10/00 20130101; C08F 210/00 20130101; C08F 290/042 20130101;
C08F 212/36 20130101; C08F 2500/03 20130101; C08F 210/16 20130101;
C08F 255/02 20130101; C08F 210/18 20130101; C08F 210/06 20130101;
C08F 2500/06 20130101; C08F 210/14 20130101; C08F 2500/25 20130101;
C08F 2500/25 20130101; C08F 236/20 20130101; C08F 4/65927 20130101;
C08F 2500/03 20130101; C08F 4/6543 20130101; C08F 2500/03 20130101;
C08F 2500/03 20130101; C08F 2500/06 20130101; C08F 2500/25
20130101; C08F 236/20 20130101; C08F 236/20 20130101; C08F 2500/25
20130101; C08F 210/06 20130101; C08F 236/20 20130101; C08F 2500/03
20130101; C08F 2500/03 20130101; C08F 210/14 20130101; C08F 2500/03
20130101; C08F 2500/06 20130101; C08F 212/08 20130101; C08F 236/20
20130101; C08F 2500/06 20130101; C08F 2500/03 20130101; C08F 210/02
20130101; C08F 236/20 20130101; C08F 210/02 20130101; C08F 255/02
20130101; C08F 10/00 20130101; C08F 4/65912 20130101; C08F 210/06
20130101; C08F 10/00 20130101 |
Class at
Publication: |
526/336 ;
526/126; 526/127; 526/134; 526/160; 526/170; 526/943; 526/348.2;
525/105; 525/250; 525/259; 525/285 |
International
Class: |
C08F 236/20 |
Claims
What is claimed is:
1. A linear, homogeneous copolymer comprising alpha-olefin and
divinylbenzene comonomer units, and having the structural formula:
15wherein R is a member selected from the group consisting of
linear and branched alkyl groups and cyclic aliphatic and aromatic
groups; x is the mole % of ethylene-derived units in the copolymer;
y is the mole % of alpha-olefin-derived units in the copolymer,
other than ethylene-derived units; x+y is the combined alpha-olefin
mole % in the copolymer and is between about 50 and 99.9%; z is the
mole % of units in the copolymer that are derived from
divinylbenzene; and the sum of x+y+z is 100%; said copolymer having
a ratio of total unsaturation/divinylbenzene (TUS/DOU) between 0.8
and 1.1, a number average molecular weight (Mn) of at least 1,000,
and a ratio of weight average molecular weight to number average
molecular weight (Mw/Mn) of less than 4; and wherein said
divinylbenzene comonomer units are derived from a divinylbenzene
selected from the group consisting of 1,4-divinylbenzene, mixtures
of 1,4-divinylbenzene and 1,3-divinylbenzene, and mixtures of
1,4-divinylbebzene, 1,3-divinylbenzene and 1,2-divinylbebzene.
2. A linear copolymer according to claim 1, wherein the copolymer
is a poly(ethylene-co-divinylbenzene), wherein y is 0, wherein x is
at least 60%, and wherein the number average molecular weight of
the copolymer is at least 10,000.
3. A linear copolymer according to claim 1, wherein the copolymer
is a poly(propylene-co-divinylbenzene), wherein x is 0, wherein y
is the mole % of propylene-derived units in the copolymer and is at
least 60%, and wherein the number average molecular weight of the
copolymer is at least 10,000.
4. A linear copolymer according to claim 1, wherein the copolymer
is a poly(1-butene-co-divinylbenzene), wherein x is 0, wherein y is
the mole % of 1-butene-derived units in the copolymer and is at
least 60%, and wherein the number average molecular weight of the
copolymer is at least 10,000.
5. A linear copolymer according to claim 1, wherein the copolymer
is a poly(1-octene-co-divinylbenzene), wherein x is 0, wherein y is
the mole % of 1-octene-derived units in the copolymer and is at
least 60%, and wherein the number average molecular weight of the
copolymer is at least 10,000.
6. A linear copolymer according to claim 1, wherein the copolymer
is a poly(ethylene-ter-propylene-ter-divinylbenzene), wherein x is
greater than 0, wherein y is the mole % of propylene-derived units
in the copolymer and is greater than 0, wherein the sum of x+y is
at least 60%, and wherein the number average molecular weight of
the copolymer is at least 10,000.
7. A linear copolymer according to claim 1, wherein the copolymer
is a poly(ethylene-ter-1-octene-ter-divinylbenzene), wherein x is
greater than 0, wherein y is the mole % of 1-octene-derived units
in the copolymer and is greater than 0, wherein the sum of x+y is
at least 60%, and wherein the number average molecular weight of
the copolymer is at least 10,000.
8. A process for preparing a linear, homogeneous copolymer
comprising alpha-olefin and divinylbenzene comonomer units, and
having the structural formula: 16wherein R is a member selected
from the group consisting of linear and branched alkyl groups and
cyclic aliphatic and aromatic groups; x is the mole % of
ethylene-derived units in the copolymer; y is the mole % of
alpha-olefin-derived units in the copolymer, other than
ethylene-derived units; x+y is the combined alpha-olefin mole % in
the copolymer and is between about 50 and 99.9%; z is the mole % of
units in the copolymer that are derived from divinylbenzene; and
the sum of x+y+z is 100%; and wherein said copolymer has a ratio of
total unsaturation/divinylbenzene (TUS/DOU) between 0.8 and 1.1, a
number average molecular weight (Mn) of at least 1,000, and a ratio
of weight average molecular weight to number average molecular
weight (Mw/Mn) of less than 4, which comprises: contacting
alpha-olefin monomer and a divinylbenzene monomer selected from the
group consisting of 1,4-divinylbenzene, mixtures of
1,4-divinylbenzene and 1,3-divinylbenzene and mixtures of
1,4-divinylbenzene, 1,3-divinylbenzene and 1,2-divinylbenzene,
under copolymerization reaction conditions and in the presence of a
single site metallocene catalyst having substituted
covalently-bridged ring ligands and having the structural formula
17.phi.=.angle.L-M-L'wherein M is a transition metal selected from
group consisting of Group 3 and Group 4 metals of the Periodic
Table of the Elements; wherein L and L', independently, are
selected from --NR'--, --PR'--, cyclopentadienyl and substituted
cyclopentadienyl groups bound in an .eta..sup.5 bonding mode to
said metal M; wherein at least one of L and L' is a
cyclopentadienyl or substituted cyclopentadienyl group; wherein Y
is a moiety selected from --SiR'.sub.2--, --CR'.sub.2--, and
--CR'.sub.2--CR'.sub.2--; wherein R', independently, is selected
from hydrogen, alkyl, aryl, silyl, halogenated alkyl, halogenated
aryl, and mixtures thereof; wherein X is selected from hydride,
halo, alkyl, aryl, aryloxy, and alkoxy; wherein n is 0, 1 or 2; and
wherein .PHI. is the angle formed at the metal center between two L
and L' ligands and is between 135 and 105.degree..
9. The process according to claim 8, wherein the alpha-olefin
monomer and divinylbenzene monomer are contacted in the further
presence of a cocatalyst for activating the single site metallocene
catalyst.
10. The process according to claim 9, wherein M is selected from
zirconium and titanium, and wherein said cocatalyst is a Bronsted
acid salt with a noncoordinating anion.
11. The process according to claim 9, wherein the alpha-olefin
monomer and divinylbenzene monomer are contacted in the presence of
a reaction diluent selected from aliphatic and aromatic
hydrocarbons.
12. The process according to claim 11, wherein said reaction
diluent is selected from the group consisting of propane, butane,
cyclopentane, hexane, toluene, heptane, isooctane and mixtures
thereof.
13. The process according to claim 8, wherein said copolymer is
formed as a slurry of particles in said reaction diluent.
14. The process according to claim 8, wherein said copolymer is
soluble in said reaction diluent and wherein the process takes
place as a homogeneous solution process.
15. Functionalized polyolefins and graft copolymers (II) having the
structural formula 18in which: R is a member selected from alkyl
groups, cyclic aliphatic groups and aromatic groups; G and G',
independently, are selected from --H, --OH, epoxy, --NH.sub.2,
--COOH, anhydride, --Cl, --Br, --M, --COOM (wherein M=metal) and a
polymer chain having the molecular weight of at least about 500; x
is.gtoreq.0; y is.gtoreq.0; m is .gtoreq.0; n is at least 0.05%;
the combined alpha-olefin mole % (x+y) is between about 50 and
99.9%; the sum of x, y, m and n is 100%; and the backbone polymer
chain has a number average molecular weight (Mn) of at least about
1,000; said copolymers (II) being derived from linear polyolefin
copolymers (I) that (a) comprises alpha-olefin and divinylbenzene
comonomer units, (b) has a linear molecular structure with an
unsaturation/divinylbenzene (TUS/DOU) mole ratio near unity, (c)
has a ratio of weight average molecular weight (Mw) to number
average molecular weight, or Mw/Mn, less than about 4, and (d) has
narrow composition distribution with the incorporated
divinylbenzene units being distributed homogeneously along the
polyolefin chains; wherein said divinylbenzene comonomer units are
selected from the group consisting of 1,4-divinylbenzene comonomer
units, mixtures of 1,4-divinylbenzene and 1,3-divinylbenzene
comonomer units and mixtures of 1,4-divinylbenzene,
1,3-divinylbenzene and 1,2-divinylbenzene comonomer units.
16. The copolymer (II) of claim 15, where y is 0%, x is greater
than 60% and the backbone of the copolymer (II) is polyethylene
having a number average molecular weight (Mn) of at least about
10,000.
17. The copolymer (II) of claim 15, where R is a methyl group, x is
0%, y is between 85 and 99.9%, and the backbone of the copolymer
(II) is an isotactic polypropylene structure having a number
average molecular weight (Mn) of at least about 10,000.
18. The copolymer (II) of claim 15, where R is a C.sub.6 alkyl
group, x is 0%, y is greater than 60%, and the backbone of the
copolymer (II) is poly(1-octene) having a number average molecular
weight (Mn) of at least about 10,000.
19. The copolymer (II) of claim 15, where R is methyl group, x is
at least about 40%, y is at least about 30%, the sum of x+y is
between 85 and 99.9%, and the backbone of copolymer (II) is an EP
elastomer having a number average molecular weight (Mn) of at least
about 10,000.
20. The copolymer (II) of claim 15, where R is a C.sub.6 alkyl
group, x is at least about 40 %, y is at least about 30%, and the
backbone of copolymer (II) is an ethylene/l-octene elastomer having
a number average molecular weight (Mn) of at least about
10,000.
21. The copolymer (II) of claim 15, where G and G', independently,
are polyethylene having a number average molecular weight (Mn) of
at least about 1,000.
22. The copolymer (II) of claim 15, where G is hydrogen and G' is
isotactic polypropylene having a number average molecular weight
(Mn) of at least about 10,000.
23. The copolymer (II) of claim 15, where G is hydrogen and G' is
isotactic polybutene having a number average molecular weight (Mn)
of at least about 10,000.
24. The copolymer (II) of claim 5, where G and G', independently,
are syndiotactic polystyrene having a number average molecular
weight (Mn) of at least about 5,000.
25. The copolymer (II) of claim 15, where at least one of G and G'
comprises a polymer or copolymer of a transition metal
polymerizable monomer selected from the group consisting of
ethylene, propylene, 1-butene, 1-hexane, 1-octene, styrene,
p-methylstyrene, p-chlorostyrene, norbomene and norbomene
derivatives, and mixtures thereof.
26. The copolymer (II) of claim 15, where G and G', independently,
are selected from the group consisting of polymers and copolymers
of anionically polymerizable monomers.
27. The copolymer (II) of claim 26, wherein said anionically
polymerizable monomers are selected from the group consisting of
styrene, butadiene, isoprene, alkyl acrylates, alkyl methacrylates,
vinyl unsaturated amides, methacrylonitrile, acrylonitrile, vinyl
pyridienes, and mixtures thereof.
28. The copolymer (II) of claim 15, where G and G', independently,
are selected from the group consisting of polymers and copolymers
of free radically polymerizable monomers.
29. The copolymer (II) of claim 28, wherein said free radically
polymerizable monomers are selected from the group consisting of
ethylene, styrene, vinyl chloride, acrylates, methacrylates, vinyl
acetate, acrylamides, acrylonitrile and mixtures thereof.
30. The copolymer (II) of claim 15, where G and G', independently,
are selected from the group consisting of polymers and copolymers
of cationically polymerizable monomers.
31. The copolymer (II) of claim 15, where at least one of G and G'
include a linked nucleophilic residue and a polymer chain selected
from anionically ring-openable monomers, cationically ring-openable
monomers, and oxidatively coupleable monomers.
32. The copolymer (II) of claim 31, wherein said anionically and
cationically ring-openable monomers are selected from the group
consisting of cyclic ethers, sulfides, lactones, lactams and
n-carboxyanhydride.
33. A processes for preparing a graft copolymer (II) having the
structural formula 19in which: R is a C.sub.1 to C.sub.10 linear or
branched alkyl group or a C.sub.6 to C.sub.10 substituted or
unsubstituted aromatic group; G and G', independently, are selected
from --H, --OH, epoxy, --NH.sub.2, --COOH, anhydride, --Cl, --Br,
--M, --COOM (wherein M=metal) and a polymer chain having the
molecular weight of at least about 500; x is .gtoreq.0; y is
.gtoreq.0; m is .gtoreq.0; n is at least 0.05%; the combined
alpha-olefin mole % (x+y) is between about 50 and 99.9%; the sum of
x, y, m and n is 100%; and the backbone polymer chain has a number
average molecular weight (Mn) of at least about 1,000; which
comprises: contacting under polymerization reaction conditions a
monomer capable of undergoing polymerization in the presence of a
transition metal coordination catalyst with (a) a transition metal
coordination catalyst, (b) an activating co-catalyst, and (c) a
divinylbenzene comonomer unit-containing linear polyolefin
copolymer (I) having the formula 20in which: R is a C.sub.1 to
C.sub.10 linear or branched alkyl group or a C.sub.6 to C.sub.10
substituted or unsubstituted aromatic group; x is .gtoreq.0; y is
.gtoreq.0; the combined alpha-olefin mole % (x+y) is between about
50 and 99.9%; and the sum of x, y, and z is 100%; and in which the
backbone polymer chain has a number average molecular weight (Mn)
of at least about 1,000, a ratio of weight average molecular weight
(Mw) to number average molecular weight (Mw/Mn) less than about 4,
a linear molecular structure, and a narrow composition distribution
with the incorporated divinylbenzene units being distributed
homogeneously along the backbone polymer chains; said incorporated
divinylbenzene units being selected from the group consisting of
1,4-divinylbenzene units, mixtures of 1,4-divinylbenzene and
1,3-divinylbenzene units and mixtures of 1,4-divinylbenzene,
1,3-divinylbenzene and 1,2-divinylbenzene units.
34. The process of claim 33, wherein the polymerizable monomer, the
catalyst, the co-catalyst and the copolymer (I) are contacted in an
inert diluent under suspension polymerization reaction
conditions.
35. The process of claim 33, wherein the polymerizable monomer, the
catalyst, the co-catalyst and the copolymer (I) are contacted in an
inert solvent under homogeneous solution polymerization reaction
conditions.
36. The process of claim 33, wherein the catalyst that is employed
is a transition metal coordination catalyst system comprising a
metallocene coordination compound and a noncoordinating anion.
37. The process of claim 33, wherein said metallocene compound
comprises a titanocene or zirconocene compound having at least one
cyclopentadienyl moiety.
Description
RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 09/359,345, filed on Jul. 21, 1999 (now U.S.
Pat. No. 6,096,849) and of U.S. application Ser. No. 09/573,737,
filed on May 18, 2000.
FIELD OF THE INVENTION
[0002] The invention relates to a process for copolymerizing
alpha-olefins and divinylbenzene, which process utilizes certain
metallocene catalysts to produce alpha-olefin/divinylbenzene
copolymers having a linear copolymer structure and narrow molecular
weight and composition distributions, and to a process for
preparing polyolefin graft copolymers containing polyolefin
backbone and pendant polymer side chains derived from both chain
and step growth polymerization reactions. The process for preparing
the graft copolymers includes functionalization and graft
copolymerization reactions utilizing the linear copolymers of
alpha-olefins and divinylbenzene, which have been prepared using
certain metallocene catalysts.
[0003] The invention also relates to the linear
alpha-olefin/divinylbenzen- e copolymers and to the polyolefin
graft copolymers that are prepared in accordance with the processes
of this invention.
BACKGROUND OF THE INVENTION
[0004] Although useful in many commercial applications, polyolefin
homopolymers, such as high density polyethylene (HDPE) and
isotactic polypropylene (i-PP), suffer poor interaction with other
materials. The inert nature of polyolefins significantly limits
their end uses, particularly those in which adhesion, dyeability,
paintability, printability or compatibility with other functional
polymers is paramount.
[0005] Unfortunately, because of their inert nature and
crystallinity, polyolefins have been among the more difficult
materials to chemically modify by means of post-polymerization
processes. In many cases, the post-polymerization reactions result
in serious side reactions, such as degradation and crosslinking
reactions. Although the direct copolymerization is the most
effective route to functionalize polyolefins, such direct processes
usually are laden with difficulties and limitations.
[0006] Only the transition metal coordination catalysts
(Ziegler-Natta and metallocene catalysts) can be used in the
preparation of linear polyolefins, and it normally is difficult to
incorporate functional group-containing monomers into the
polyolefins by using the early transition metal catalysts due to
catalyst poisoning (see J. Boor, Jr., Ziegler-Natta Catalysts and
Polymerizations, Academic Press, New York, 1979). The Lewis acid
components (Ti, V, Zr and Al) of the catalyst will tend to complex
with nonbonded electron pairs on N, O, and X (halides) of
functional monomers in preference to complexation with the
.pi.-electrons of the double bonds. The net result is the
deactivation of the active sites by formation of stable complexes
between catalysts and functional groups, thus inhibiting
polymerization.
[0007] In several prior art disclosures, it has been taught to
prepare reactive polyolefin copolymers containing either borane
(see U.S. Pat. Nos. 4,734,472; 4,751,276; 4,812,529; 4,877,846) or
p-methylstyrene (see U.S. Pat. Nos. 5,543,484; 5,866,659 and
6,015,862; and J. Polym. Sci. Polym Chem., 36, 1017, 1998; J.
Polym. Sci. Polym Chem., 37, 2795, 1999; and Macromolecules, 31,
2028, 1998) reactive comonomer units. The chemistry disclosed in
this prior art involves the direct copolymerization of
alpha-olefins and organoborane-substituted monomers and
p-methylstyrene, respectively, with Ziegler-Natta and metallocene
catalysts. The homo- and copolymers containing reactive borane or
p-methylstyrene groups are very useful intermediates for preparing
a series of functionalized polyolefins. Many new functionized
polyolefins with various molecular architectures have been obtained
based on this chemistry. In addition, it has been demonstrated that
polar groups can improve the adhesion of polyolefins to many
substrates, such as metals and glass (see Chung et al, J.
Thermoplastic Composite Materials, 6, 18, 1993 and Polymer, 35,
2980, 1994). The application of both borane-containing polymers and
p-methylstyrene-containing polymers also has been extended to the
preparation of polyolefin graft copolymers, which involves free
radical (see U.S. Pat. Nos. 5,286,800 and 5,401,805; Chung et al,
Macromolecules, 26, 3467, 1993; and Chung et al, Macromolecules,
32, 2525, 1999) and anionic graft-from reactions (see Chung et al,
Macromolecules, 30, 1272, 1997), respectively. In polymer blends,
compatibility of the polymers can be improved by adding a suitable
polyolefin graft copolymer which reduces the domain sizes and
increases the interfacial interaction between domains (see Chung et
al, Macromolecules, 26, 3467, 1993; Macromolecules, 27, 1313,
1994).
[0008] Another approach toward preparing functionalized polyolefins
is the preparation of unsaturated polyolefin copolymers containing
pending unsaturated side chains, which are reactive in subsequent
chemical functionalization reactions. In general, the transition
metal (Ziegler-Natta and metallocene catalysts) copolymerization of
alpha-olefin and diene monomer is a great concern with many
potential side reactions. The diene monomer, containing two
reactive sites, potentially may engage in a double addition
reaction to form copolymers having long branching side chains or
even three dimensional network (crosslinked) structures. Most of
linear diene-containing copolymers that have been reported involve
the use of asymmetric dienes (see U.S. Pat. Nos. 3,658,770;
4,680,318; and 4,366,296) which contain only one polymerizable
olefin unit, either an alpha-olefin or a constrained cycloolefin
moiety, to prevent the formation of crosslinked (unprocessible)
products. The asymetric dienes include those containing an
alpha-olefin unit and an internal olefin unit, such as
1,4-hexadiene and methyl-1,4-hexadiene, and those containing a
constrained cycloolefin unit and a linear olefin unit, such as
2-methylene-5-norborene, 5-vinyl-2-norborene and dicyclopentadiene.
Several unsaturated polyolefins have been reported, including
unsaturated polyethylene copolymers (Marathe et al. Macromolecules,
27, 1083, 1994), polypropylene copolymers (Kitagawa et al., Polymer
Bulletin, 10, 109, 1983) and ethylene-propylene terpolymers
(VerStrate et al, Encyclopedia of Polym. Sci. and Eng., 6, 522,
1986). Recently, Machida et al. (JP 05-194665 and JP 05-194666)
also reported the copolymerization of alpha-olefins and asymetric
styrenic diene comonomers, such as p-(3-butenyl)styrene, to produce
linear copolymers using Ziegler-Natta heterogeneous catalysts.
[0009] Alpha-olefin polymerization involving symmetric
alpha,omega-diene comonomers in which both double bonds are
terminal alpha-olefins are very limited. One such polymerization,
which involved the copolymerization of alpha-olefin and
1,3-butadiene (Bruzzone et al., Makromol. Chem., 179, 2173, 1978;
Cucinella et al., European Polym. J., 12, 65, 1976), resulted in
copolymers where the butadiene units in the copolymer were mostly
in the trans-1,4-configuration. In other words, both alpha-olefins
in the butadiene monomer were engaged in the polymerization
reaction. Some diene comonomers having a long spacer between two
terminal olefins, including C.sub.8-C.sub.14 aliphatic
alpha,omega-dienes, such as 1,7-octadiene, 1,9-decadiene,
1,11-dodecadiene and 1,13-tetradecadiene (see U.S. Pat. Nos.
4,551,503; 4,340,705; and 5,504,171), were found to be more
selective so as to engage only one olefin group in the
heterogeneous Ziegler-Natta copolymerization reaction. The
resulting polyolefin copolymers have pending alpha-olefin groups
located along the polymer chain.
[0010] Incorporating a divinylbenzene comonomer into a linear
polyolefin would result in polyolefin copolymers containing pending
styrene groups, as illustrated, for example, in Formula (I) where
the divinylbenzene may comprise 1,2-divinylbenzene,
1,3-divinylbenzene, 1,4-divinylbenzene or mixtures thereof. Such
copolymers could be used as versatile precursors for a broad range
of polyolefin structures, including the polyolefin graft copolymers
containing polyolefin backbone and other polymer side chains.
However, it is very difficult to prepare linear polyolefin
copolymers having a well-defined molecular structure, as
illustrated in Formula (I), due to potential branching and
crosslinking reactions, resulting from the difuntional nature of
the divinylbenzene comonomer(s).
[0011] The transition metal copolymerization of styrenic monomers
and alpha-olefins usually is very difficult to accomplish (see
Seppala et al., Macromolecules, 27, 3136, 1994 and Soga et al.,
Macromolecules, 22, 2875, 1989). This is especially true when using
stereospecific heterogeneous Ziegler-Natta catalysts having
multiple active sites, since the reactivity of monomer is
sterically controlled, i.e., the larger the size of the monomer,
the lower the reactivity; and those few styrenic copolymers that
are known tend to be very inhomogeneous (Mijatake, et al.,
Makromol. Chem. Macromol. Symp., 66, 203, 1993; Aaltonen, et al.,
Macromolecules, 27, 3136, 1994; and U.S. Pat. No. 5,543,484) and to
have broad molecular weight and composition distributions (and even
to include some homopolymer).
[0012] The copolymerization of alpha-olefin and divinylbenzene by
Ziegler-Natta catalysts has been disclosed (Yokoyama, et al., Eur.
Pat. Appl. 88310305.3 and Yoshitake, et al., JP 62-241907). It also
has been disclosed that the resulting copolymers can be used in the
preparation of polyolefin graft copolymers (Yokoyama, et al., JP
03-255114; Tomita, et al., JP 08-003231, JP 08-003232 and JP
05-017539). However, as expected, the known copolymers of
divinylbenzene and alpha-olefins, especially ethylene and
propylene, are very inhomogeneous, showing broad composition and
molecular weight distribution (Mw/Mn>6), due to multiple active
sites and sterically-controlled monomer reactivity. Also, the
extent of side reactions has not been reported, possibly because it
may be very difficult to determine the extent of side reactions due
to the very low concentration of divinylbenezene in the copolymer
products. The divinylbenzene content in the ethylene and propylene
copolymers is below 0.3 mole % (1 wt %) and the overall
divinylbenzene conversion is only few % in each case. In general,
the catalyst activity is inversely proportional to the
concentration of divinylbenzene in the monomer feed.
[0013] Machida, et al. (U.S. Pat. No. 5,608,009) also reported the
copolymerization reaction of ethylene and diene comonomers
(including diene compounds having aromatic rings including
divinylbenzene and others) by using metallocene catalysts. The
diene-containing copolymers were used as intermediates in the
preparation of graft copolymers, including long chain branching
polyolefins. In general, the alpha-olefin/divinylbenzene copolymers
reported by Machida, et al. were complex and had ill-defined
molecular structures. Moreover, Machida, et al. failed to identify
the reaction conditions that are necessary to prepare copolymers
having a linear molecular structure and narrow composition and
molecular weight distributions (as discussed in Column 16, lines
41-45, the olefin copolymers obtained by Machida, et al. were
long-branched copolymers). The disclosed examples of
copolymerization reactions between ethylene and divinylbenzene
involved using dicyclopentadienylzirconium dichloride (in Example
1) and cyclopentadienylzirconium trimethoxide (in Example 3) as the
catalyst system. The molecular structures of the resulting
ethylene/divinylbenzene copolymers were complex and the copolymers
were characterized by a low molecular weight (Mw=5,670 in Example 1
and Mw=14,500 in Example 3) and broad molecular weight
distributions (Mw/Mn=6.6 in Example 1 and Mw/Mn=23 in Example 3).
The inhomogeneous and non-linear copolymer structures were clearly
revealed by the ratio of unsaturation/divinylbenzene (TUS/DOU) in
the copolymers, the ratios being 0.71 (in Example 1) and 7.55 (in
Example 3) using dicyclopentadienylzirconium dichloride and
cyclopentadienyltitanium trimethoxide, respectively.
[0014] It is well known that metallocene polymerization results in
polymers that are terminated mainly by beta-hydride elimination to
form an unsaturated site at the chain end. Accordingly, it would be
logical that the TUS/DOU ratio should be near unity for a linear
copolymer of the type contemplated by the present invention, as
illustrated in Formula (I). Thus, for a linear polymer, it would be
expected that as the polymerization reaction continues and as the
molecular weight increases (and as divinylbenzene units become
incorporated into the copolymer), the contribution of chain end
unsaturation to the TUS/DOU ratio would be very small. In other
words, the TUS/DOU ratio should remain at or very close to unity.
Similarly, it would be logical to assume that a copolymer that is
characterized by a TUS/DOU ratio that deviates substantially from
unity would be a non-linear, inhomogeneous copolymer containing
many chain ends. For the known ethylene/divinylbenzene copolymers
that were prepared using dicyclopentadienylzirconium dichloride
(Example 1, above), the ratio of TUS/DOU=0.71 strongly suggests
that a good portion of the divinylbenzene units that were
incorporated into the copolymer had undergone double addition
reactions at both vinyl groups to produce a polymer having a
long-chain branching structure. Overall, the prior disclosures fail
to identify the reaction conditions, especially the catalyst
systems, which are necessary to prepare linear
alpha-olefin/divinylbenzene copolymers having narrow composition
and molecular weight distributions.
[0015] Machida, et al. (Eur. Pat. Appl. 93103181.9 (Pub. No. 0 559
108 A1)) also reported the application of the copolymerization
adducts of alpha-olefin and diolefin comonomers (including
divinylbenzene) for the preparation of graft copolymer containing
syndiotactic polystyrene (s-PS) side chains. The results clearly
demonstrated the disadvantages of using divinylbenzene as the
diolefin unit under their reaction conditions. The problems include
the formation of crosslinked product, difficulty in assuring
sufficient reactivity and monomers remaining unreacted. In fact,
the graft copolymers with much better quality were prepared by
using other diolefin monomers.
[0016] In general, the advances in metallocene catalysts (see U.S.
Pat. Nos. 4,542,199; 4530,914; 4,665,047; 4,752,597; 5,026,798 and
5,272,236) provide an excellent opportunity for chemists to prepare
new polyolefin polymers. With well-defined (single-site) catalysts
and a designed active site geometry, monomer insertion can be
controlled effectively, both kinetically and sterically, during a
polymerization process. This is especially important for
copolymerization reactions for producing copolymers having a
relatively well-defined molecular structure. Several prior
publications have disclosed the use of metallocene catalysts having
a constrained ligand geometry for producing narrow composition
distribution and narrow molecular weight distribution linear low
density polyethylene (LLDPE).
[0017] For copolymerization reactions, use of a relatively opened
active site metallocene catalyst provides essentially equal access
for both comonomers, and the incorporation of higher molecular
weight olefin comonomer is significantly higher than for those
copolymers obtained from traditional Ziegler-Natta catalysts. In
fact, some metallocene catalysts with constrained ligand geometry
and opened active site have been shown to be effective for
incorporation of styrenic monomers in polyolefin copolymers,
including poly(ethylene-co-styrene) (U.S. Pat. No. 5,703,187),
poly(ethylene-co-p-methylstyrene), poly(ethylene-ter-propylen-
e-ter-p-methylstyrene) and
poly(ethylene-ter-1-octene-ter-p-methylstyrene) (U.S. Pat. No.
5,543,484, and J. Polym. Sci. Polym Chem., 36, 1017, 1998,
Macromolecules, 31, 2028, 1998).
SUMMARY OF THE INVENTION
[0018] The invention relates to copolymers containing alpha-olefin
and divinylbenzene comonomer units, which copolymers have a linear
molecular structure and are characterized by a mole ratio of
unsaturation/divinylbenzene (TUS/DOU) near unity. The copolymers
are also characterized by a narrow molecular weight distribution
and a narrow composition distribution, and may be represented by
the following structural Formula (I): 3
[0019] in which R is a linear or branched alkyl group, or a cyclic
aliphatic or aromatic group, x represents the mole % of ethylene
units in the copolymer, y represents the mole % of alpha-olefin
comonomer units in the copolymer, and z represents the mole %
divinylbenzene units in the copolymer. Preferably, R is a C.sub.1
to C.sub.10 linear or branched alkyl group or a C.sub.6 to C.sub.10
substituted or unsubstituted aromatic group, and most preferably, R
is C.sub.1 to C.sub.6 alkyl group or substituted or unsubstituted
C.sub.6 aromatic group. The value of x may vary from 0% to about
99.9%, as may the value of y; provided, however, that the combined
value of alpha-olefin mole % (x+y) in the copolymer is between
about 50 and 99.9%. Preferably, x+y is between 85 and 99.9%, and
most preferably x+y is between 95 and 99.9%. The sum of x, y and z
(mole % of divinylbenzene) is 100%. The mole ratio of
unsaturation/divinylbenzene (TUS/DOU) in the copolymers is near
unity, typically between 0.8 and 1.1. Preferably, the TUS/DOU ratio
is between 0.9 and 1, and most preferably ratio is between 0.95 and
1. The copolymers of this invention have a number average molecular
weight (Mn) of at least about 1,000, and preferably at least about
10,000. The copolymers also preferably have a molecular weight
distribution (ratio of weight average molecular weight (Mw) to
number average molecular weight (Mn), or Mw/Mn) of less than about
4. Preferably, Mw/Mn is less than 3. Furthermore, the copolymers
have narrow composition distribution with the incorporated
divinylbenzene units being distributed homogeneously along all of
the polymer chains.
[0020] The invention also relates to a polymerization process for
producing alpha-olefin/divinylbenzene copolymers (I) having a
linear molecular structure, a mole ratio of
unsaturation/divinylbenzene (TUS/DOU) near unity, and narrow
molecular weight and composition distributions. The process
involves contacting the alpha-olefin and divinylbenzene comonomers
under copolymerization reaction conditions in the presence of a
single-site metallocene catalyst having substituted
covalently-bridged ring ligands and a specific opening at the metal
active site, as illustrated below: 4 .phi.=.angle.L-M-L'
[0021] where M is a transition metal of group 3 or group 4 of the
Periodic Table of the Elements; L and L', independently, are
selected from --NR'--, --PR'--, cyclopentadienyl or substituted
cyclopentadienyl groups bound in an .eta..sup.5 bonding mode to M,
wherein at least one of L and L' is a cyclopentadienyl or a
substituted cyclopentadienyl group, and wherein each occurrence of
R', independently, is selected from the group consisting of
hydrogen, alkyl, aryl, silyl, halogenated alkyl, halogenated aryl,
and mixtures thereof, Y is a moiety selected from --SiR'.sub.2--,
--CR'.sub.2--, and --CR'.sub.2--CR'.sub.2--; X is selected from
hydride, halo, alkyl, aryl, aryloxy, and alkoxy; and n is 0, 1 or
2; and the angle, .phi., formed at the metal center between two L
and L' ligands, such as the centroid of two cyclopentadienyl or
substituted cyclopentadienyl groups, is between 135.degree. and
105.degree.. Preferably, the value of .phi. is between 130.degree.
and 115.degree., and most preferably, the value of .phi. is between
128.degree. and 120.degree..
[0022] The constrained ligand geometry associated with the
covalently-bridged ligands results in a specific space opening at
the metal active site, which provides the selective reaction with
only one of the two vinyl groups in divinylbenzene during the
copolymerization between alpha-olefins and divinylbenzene. In other
words, the catalysts contemplated for use in the present invention
can effectively incorporate divinylbenzene into the copolymer chain
through single enchainment, but show poor reactivity to the
styrenic units already existing in the copolymer (I).
[0023] The metallocene catalysts contemplated for use in this
invention may be used as such. However, as is known, the catalysts
may be used in conjunction with a cocatalyst or activator, such as
aluminoxane and tris(pentafluorophenyl)borane.
[0024] In accordance with another embodiment of the invention,
functionalized polyolefins and graft copolymers are prepared by
chemically reacting the pending styrene units in the
alpha-olefin/divinylbenzene copolymers (I). The resulting
functionalized polyolefins and graft copolymer may be illustrated
in Formula (II), below 5
[0025] in which R is defined above in connection with Formula (I).
G and G', independently, are selected from --H, --OH, epoxy,
--NH.sub.2, --COOH, anhydride, --Cl, --Br, --M, --COOM (M=metals,
e.g. Li, Na, K and Ca) or a polymer chain having a molecular weight
of at least about 500, which can be derived from both step and
chain polymerization reactions; x and y are as previously defined
in connection with Formula (I); m is the mole % of divinylbenzene
units remaining in the functionalized copolymer; n is the mole % of
functionalized styrenic units and is at least 0.1%; and the sum of
x, y, m and n is 100%. As indicated in connection with Formula (I),
the combined alpha-olefin mole % (x+y) in the functionalized
copolymer (Formula (II)) is between about 50 and 99.09%.
Preferably, x+y is between 85 and 99.9%, and most preferably x+y is
between 95 and 99.9%. The sum of x, y, m and n is 100%, and n is at
least 0.05%. The backbone polymer chain has a number average
molecular weight (Mn) of at least about 1,000, and preferably at
least about 10,000.Typically, the backbone polymer chain has a
number average molecular weight (Mn) of from about 20,000 to about
200,000.
[0026] In one aspect of the invention, applicants have discovered
the reaction processes for producing functionalized polyolefins and
graft copolymers (II) by the chemical reactions of pending styrene
units in alpha-olefin/divinylbenzene copolymers (I), which have a
linear molecular structure and narrow molecular weight and
composition distributions. The linear copolymers have monomer units
which may be represented by the structural formula, 6
[0027] in which R is an alkyl group, or a cyclic aliphatic or
aromatic group. Preferably, R is C.sub.1 to C.sub.10 linear or
branched alkyl group, or a C.sub.6 to C.sub.10 substituted or
unsubstituted aromatic group, and most preferably, a C.sub.1 to
C.sub.6 alkyl group or a substituted or unsubstituted C.sub.6
aromatic group. In the copolymer composition, the combined
alpha-olefin mole % (x+y) is between about 50 and 99.9 mole %.
Preferably, x+y is between 85 and 99.9 mole %, and most preferably
x+y is between 95 and 99.9 mole %. The sum of x, y and z (mole % of
divinylbenzene) is 100%. The copolymer (I) has a number average
molecular weight (Mn) of at least about 1,000, and preferably at
least about 10,000 (typically from at least about 20,000). The
copolymers also preferably have a ratio of weight average molecular
weight (Mw) to number average molecular weight, or Mw/Mn, less than
about 4. Preferably, Mw/Mn is less than 3. Furthermore, the
copolymers have narrow composition distribution with the
incorporated divinylbenzene units homogeneously distributed along
all the polymer chains.
[0028] The pendant styrene groups in the polyolefin copolymer (I)
are very versatile, and can be converted to functional (polar)
groups, such as --OH, epoxy, --NH.sub.2, --COOH, anhydride, --Cl,
--Br, --M, --COOM (M=metal, e.g. Li, Na, K and Ca), by conventional
organic olefinic chemistry. The resulting converted copolymer
contains pendant functional groups, which can further serve as the
coupling sites for reacting with a polymer having a terminal
reactive group to form a graft copolymer (II). With the careful
selection of a coupling pair, a coupling reaction can take place
effectively in solution or melt. A coupling reaction also can be
accomplished during a reactive extrusion process. Furthermore, it
is very convenient to prepare graft copolymer (II) by using the
pendant styrene groups in the polyolefin copolymer (I) as a monomer
unit in a subsequent polymerization process. In other words, a
second copolymerization reaction involving copolymer (I) and
olefinic monomers can take place via either a graft-onto or a
graft-through process to produce graft copolymer (II), containing
polyolefin backbone and several pendant polymer side chains.
[0029] As illustrated in Formulas (I) and (II), the incorporated
divinylbenzene-derived units are derived from 1,4-divinylbenzene.
However, it will be appreciated that the incorporated
divinylbenzene-derived units could be derived from
1,3-divinylbenzene or, possibly, from 1,2-divinylbenzene, or from
mixtures of two or more of 1,4-divinylbenzene, 1,3-divinylbenzene
and 1,2-divinylbenzene. In fact, the divinylbenzene comonomer that
would used to prepare the linear copolymers of the present
invention typically would comprise mixtures of 1,4-divinylbenzene
and 1,3-divinylbenzene, possibly with some small amount of
1,2-divinylbenzene. Commercially available divinylbenzene
compositions typically comprise a mixture of 1,3- and
1,4-divinylbenzene in a weight ratio of from about 1:1 to about
1:4, e.g., about 1:2.5. Accordingly, unless specifically stated
otherwise, the term "divinylbenzene" is used in this specification
and claims to include 1,4-divinylbenzene, individually,
1,3-divinylbenzene, individually, as well as mixtures of 1,4- and
1,3-divinylbenzene or mixtures of 1,4-, 1,3- and
1,2-divinylbenzene. Similarly, unless specifically stated
otherwise, when divinylbenzene-derived units are illustrated in
this specification and claims, as in Formulas (I) and (II), as
being derived from 1,4-divinylbenzene, the illustration is meant to
include units derived from 1,4-divinylbenzene, individually, from
1,3-divinylbenzene, individually, as well as units derived from
mixtures of 1,4- and 1,3-divinylbenzene and from 1,4-, 1,3-and
1,2-divinylbenzene. In preferred aspects of the invention, the term
"divinylbenzene" is used to describe 1,4-divinylbenzene or mixtures
of 1,4- and 1,3-divinylbenzene.
DETAILED DESCRIPTION
[0030] This invention is based on the discovery that with certain
metallocene catalysts the effective copolymerization reaction of
alpha-olefin and divinylbenzene can take place to produce
alpha-olefin/divinylbenzene copolymers having a linear copolymer
structure. The unsaturation/divinylbenzene (TUS/DOU) ratio in the
copolymers (I) is near unity, the copolymers do not contain any
substantial branching or crosslinking (no branching or crosslinked
structures were detected in the copolymers that were produced), and
the copolymers are completely soluble and processible. The
copolymers comprise the direct copolymerization product of
alpha-olefin having from 2 to 12 carbon atoms and divinylbenzene,
and are high molecular weight linear polymers having a
substantially homogeneous molecular structure, i.e. narrow
molecular weight and composition distributions. The copolymers may
be illustrated by the following formula: 7
[0031] in which R is a linear or branched alkyl group or a cyclic
aliphatic or aromatic group. Preferably, R is C.sub.1 to C.sub.10
linear and branched alkyl or a C.sub.6 to C.sub.10 substituted or
unsubstituted aromatic group, and most preferably R is C.sub.1 to
C.sub.10 alkyl group or a C.sub.6 substituted or unsubstituted
aromatic group, e.g. phenyl or alkyl-substituted phenyl.
[0032] The TUS/DOU ratio is near unity, and typically is between
0.8 and 1.1. Preferably, the TUS/DOU ratio is between 0.9 and 1,
and most preferably ratio is between 0.95 and 1. In the formula
(I), x represents the mole % of ethylene units in the copolymer, y
represents the mole % of alpha-olefin comonomer units in the
copolymer, and z represents the mole % divinylbenzene units in the
copolymer. The value of x may vary from 0% to about 99.9%, as may
the value of y; provided, however, that the combined value of
alpha-olefin mole % (x+y) in the copolymer is between about 50 and
99.9%. Typically, one of x or y is greater than 40 mole %, and in
many preferable cases, one of x or y is greater than 60 mole %.
Preferably, x+y is between 85 and 99.9%, and most preferably x+y is
between 95 and 99.9%. The sum of x, y and z (mole % of
divinylbenzene) is 100%.
[0033] The copolymers of this invention have a number average
molecular weight (Mn) of at least about 1,000, and preferably at
least about 10,000. Typically, the copolymers have a number average
molecular weight of from about 20,000 up to about 200,000 The
copolymers also preferably have a molecular weight distribution
(ratio of weight average molecular weight (Mw) to number average
molecular weight (Mn), or Mw/Mn) of less than about 4. Preferably,
Mw/Mn is less than 3, for example, from about 1.9 to about 2.8.
Furthermore, the copolymers0 have narrow composition distribution
with the incorporated divinylbenzene units homogeneously
distributed along all the polymer chains.
[0034] As disclosed herein, and as illustrated in the Tables, the
copolymerization of alpha-olefin (such as ethylene and propylene)
and divinylbenzene using a metallocene (single-site) coordination
catalyst is greatly dependent on the geometry of the active site.
The metallocene catalysts having non-bridged ligand geometry, such
as dicyclopentadienylzirconium dichloride/methylaluminoxane, have a
very limited opening at the active metal site
(.phi.>135.degree.) and greatly favor the incorporation of small
size monomers. Therefore, only very low % of divinylbenzene can be
incorporated into the copolymers having ethylene and propylene
monomer units when using a non-bridged metallocene as the catalyst.
On the other hand, metallocene catalysts having highly constrained
ligand geometry, and which have active sites that are very opened
(.phi.<105.degree.), are capable of copolymerizing
alpha-olefin(s) and divinylbenzene. However, when using metallocene
catalysts having such very open active sites (i.e.
.phi.<105.degree.) double enchainment of both vinyl groups in
divinylbenzene comonomer is highly likely to occur during the
copolymerization process, which results in copolymers having
branched or/and crosslinked structures.
[0035] Thus, the invention involves the use of metallocene
catalysts having a specific ligand geometry and a specified opening
at the active metal site, which can effectively and selectively
react with only one of the two vinyl groups in the divinylbenzene
comonomer during alpha-olefin and divinylbenzene copolymerization
reactions. The specific single-site metallocene catalysts
contemplated for use in the present invention have substituted
covalently-bridged ring ligands are illustrated below. 8
.phi.=.angle.L-M-L'
[0036] wherein M is a transition metal of group 3 or 4 of the
Periodic Table of the Elements; L and L', independently, are
selected from --NR'--, --PR'--, cyclopentadienyl or substituted
cyclopentadienyl groups bound in an .eta..sup.5 bonding mode to M,
wherein at least one of L and L' is a cyclopentadienyl or
substituted cyclopentadienyl group, and wherein each occurrence of
R', independently, is selected from the group consisting of
hydrogen, alkyl, aryl, silyl, halogenated alkyl, halogenated aryl,
and mixtures thereof; Y is a moiety selected from --SiR'.sub.2--,
--CR'.sub.2--, and --CR'.sub.2--CR'.sub.2--, where R' is as
previously defined; X is selected from hydride, halo, alkyl, aryl,
aryloxy, and alkoxy; and n is 0, 1 or 2.
[0037] The catalysts to be used in this invention are further
defined by a geometry angle, .phi., formed at the metal center
between two L and L' ligands, such as the centroid of two
cyclopentadienyl or substituted cyclopentadienyl groups. The value
of .phi. must be between 135.degree. and 105.degree.. Preferably,
the value of .phi. is between 130.degree. and 115.degree., and most
preferably, the value of .phi. is between 128.degree. and
120.degree..
[0038] Catalysts that may be used in the present invention include,
for example, ethylenebis (indenyl) zirconium dichloride,
ethylenebis (tetrahydroindenyl) zirconium dichloride, ethylenebis
(indenyl) dimethylzirconium, and the like. The amount of such
catalysts employed will depend on the desired molecular weight and
the desired molecular weight distribution of the copolymer being
produced, but will generally range from about 20 ppm to 1 wt. %,
and preferably from about 0.001 to 0.2 wt. %, based upon the total
amount of monomer to be polymerized therein.
[0039] Metallocene catalysts are known to be activated with a
co-catalyst, which typically is a Bronsted acid salt with a
noncoordinating anion. Accordingly, it is preferred to use the
metallocene catalysts in combination with a co-catalyst.
Non-limiting examples of co-catalysts that are contemplated for use
in this invention include aluminoxane,
tris(pentafluorophenyl)borane, trimethylammonium tetraphenylborate,
triethylammonium tetrakis(pentafluorophenyl)borate, and the
like.
[0040] The constrained ligand geometry associated to the
covalently-bridged ligands results in the specific space opening at
the metal active site, which provides for the selective reaction
with only one of the two vinyl groups in divinylbenzene during the
copolymerization between alpha-olefins and divinylbenzene. In other
words, the catalyst can effectively incorporate divinylbenzene into
polymer through single enchainment, but shows poor reactivity to
the styrenic units already existing in the copolymer (I). The
selective copolymerization of divinylbenzene is illustrated below:
9
[0041] Since only one vinyl group in the divinylbenzene monomer is
involved in the copolymerization reaction, the side reactions
(described in the prior art) involving pendant styrene vinyl groups
in the copolymer (I) and producing branched polymers or crosslinked
polymers can be avoided. The resulting copolymer (I) is a linear
soluble polymer having an unsaturation/divinylbenzene (TUS/DOU)
ratio near unity, e.g., between about 0.8 and 1.1. In addition, the
catalytic sites having favorable divinylbenzene incorporation
(involving only a single vinyl group) results in linear copolymers
having a broad range of divinylbenzene contents and narrow
molecular weight and composition distributions.
[0042] Suitable diluents for the monomers, catalyst components and
polymeric reaction products include the general group of aliphatic
and aromatic hydrocarbons, used singly or in a mixture, such as
propane, butane, pentane, cyclopentane, hexane, toluene, heptane,
isooctane or the like. The processes of the present invention can
be carried out in the form of a slurry of polymer formed in the
diluents employed, or as a homogeneous solution process, depending
on the alpha-olefin used. The use of a slurry process is, however,
preferred, since in that case lower viscosity mixtures are produced
in the reactor, and slurry concentrations up to 40 wt. % of polymer
are possible. At higher slurry concentrations it is possible to
operate a more efficient process in which it is necessary to
recycle less of the reactants and diluent for each unit of polymer
produced.
[0043] In general, the polymerization reactions of the present
invention are carried out by mixing divinylbenzene and alpha-olefin
(ethylene and propylene with constant pressure) in the presence of
the catalyst and diluent in a reactor, with thorough mixing, and
under copolymerization conditions, including means for controlling
the reaction temperature to between about 0 and 80.degree. C. In
particular, the polymerization may be carried out under batch
conditions, such as in an inert gas atmosphere and in the
substantial absence of moisture. Preferably, the polymerization is
carried out continuously in a typical continuous polymerization
process with inlet pipes for monomers, catalysts and diluents,
temperature sensing means, and an effluent overflow to a holding
drum or quench tank. The overall residence time can vary, depending
upon, e.g., catalyst activity and concentration, monomer
concentration, reaction temperature, monomer conversion and desired
molecular weight, and generally will be between about thirty
minutes and five hours, and preferably between about 1 and 2
hours.
[0044] The resulting copolymers typically would be weighed and
analyzed by nuclear magnetic resonance (NMR), differential scanning
calorimetry (DSC) and gel permeation chromatography (GPC) to
determine the monomer conversion, copolymer composition, thermal
transition temperature and molecular weight, respectively.
[0045] The extent of double enchainment can be quantified by
.sup.1H NMR spectrum to determine the unsaturation/divinylbenzene
(TUS/DOU) ratio of the copolymer. Thus, for a linear copolymer of
the Formula (I), without any detectable double enchainment at the
incorporated divinylbenzene units, a .sup.1H NMR spectra would show
four chemical shifts near 5.3, 5.8, 6.8 and 7.0-7.4 ppm (with the
integrated peak intensity ratio=1:1:1:4), corresponding to three
individual vinyl protons and four aromatic protons in the pending
styrene unit. One can also observe a small peak at 4.7 ppm in low
molecular weight copolymers, due to the terminal vinyl group at the
chain end. In most high molecular weight copolymer cases, the
terminal vinyl group is less than 10% of the vinyl groups derived
from divinylbenzene units. Therefore, the ratio of
unsaturation/divinylbenzene (TUS/DOU) in the linear alpha-olefin
copolymers of this invention is always near unity (typically
between about 0.8 and 1.1). A significant deviation of this peak
intensity ratio from unity indicates the extent of double bond
enchainment in the incorporated divinylbenzene units, which results
from branching and/or crosslinking in the copolymer. As will be
seen in the examples hereinbelow, a good correlation was observed
between the reduction of TUS/DOU ratio and the reduction of
copolymer processibility (solubility), due to the presence of
crosslinking in certain copolymers. In further connection with
TUS/DOU ratios, it will be appreciated that a high TUS/DOU ratio
(considerably higher 1) will be observed for low molecular weight
copolymers, which do not have any divinylbenzene units and have
only a terminal vinyl group. On the other hand, a low TUS/DOU ratio
(considerably lower than 1) would be observed if a significant
portion of the divinylbenzene units incorporated in the copolymer
engaged in double enchainment to produce a copolymer having a
long-chain branched structure.
[0046] One major advantage of the alpha-olefin and divinylbenzene
copolymers (I) is the existence of numerous pendant styrene groups
along the backbone. The pendant styrene groups are very reactive in
many chemical reactions, including free radical, cationic, anionic
and transition metal coordination reactions, and can serve as the
reactive sites for selective functionalization reactions to produce
functionalized polyolefins, or they can serve as the monomers,
initiators and chain transfer agents for subsequent graft reactions
which produce polyolefin graft copolymers having polyolefin
backbone and other polymer side chains. It will be apparent that
the reactivity of the functionalized copolymers enables subsequent
derivatization reactions to considerably broaden the copolymer
composition and structures that can be achieved.
[0047] The functionalized polyolefins and graft copolymers of the
present invention may be represented by the Formula (II),
illustrated below: 10
[0048] in which R is defined above in connection with Formula (I).
G and G', independently, are selected from --H, --OH, epoxy,
--NH.sub.2, --COOH, anhydride, --Cl, --Br, --M, --COOM (M=metal,
e.g. Li, Na, K and Ca) or a polymer chain having a molecular weight
of at least about 500, which can be derived from both step and
chain polymerization reactions; x and y are as previously defined
in connection with Formula (I); m is the mole % of divinylbenzene
units remaining in the functionalized copolymer; n is the mole % of
functionalized styrenic units and is at least 0.05% (preferably at
least 0.1%); and the sum of x, y, m and n is 100%. As indicated in
connection with Formula (I), the combined alpha-olefin mole % (x+y)
in the functionalized copolymer (Formula (II)) is between about 50
and 99.09%. Preferably, x+y is greater than 60% and is between 85
and 99.9%, and most preferably x+y is between 95 and 99.9%. The
backbone polymer chain (Formula (I)) has a number average molecular
weight (Mn) of at least about 1,000, and preferably at least about
10,000.
[0049] The functionalization reactions of
alpha-olefin/divinylbenzene copolymer (I) involve conventional
organic olefinic chemistry, which can be run in bulk, finely
dispersed slurry solution, or homogeneous polymer solution.
Usually, bulk reactions also can be effective in an extruder, or
other internal mixer, suitably modified to provide adequate mixing.
The details of such bulk processes are set forth, for example, in
U.S. Pat. No. 4,548,995, the disclosure of which is incorporated
herein by reference. Solution processes are advantageous in that
they permit good mixing and an ability to control reaction
conditions more easily. Solution processes also facilitate the
removal of undesired by-products. A disadvantage of solution
processes is the need for removing residual unreacted
divinylbenzene prior to chemical modification reactions.
[0050] Some resulting functional polyolefins contain several
pendant functional groups, such as --OH, epoxy, --NH.sub.2, --COOH,
anhydride, --Cl, --Br, that are very reactive in subsequent
coupling reactions with a polymer having a terminal reactive group
to form graft copolymer (II). The coupling reaction can be carried
out in solution or melt, and it can be accomplished during a
reactive extrusion process. One example of such a coupling reaction
is the reaction between a polyolefin (such as PP) containing
pendant succinic anhydride groups and a polyamide (such as Nylon 6)
having a terminal --NH.sub.2 group. The resulting PP-g-Nylon
contains phenylsuccinimide linkages between two types of polymer
chains. Another example of the coupling reaction is the reaction
between a polyolefin (such as PE) containing pendant succinic
anhydride groups and a poly(ethylene glycol) methyl ether having a
terminal --OH group. The resulting PE-g-PEO graft copolymer
contains phenylester linkages.
[0051] In preferred aspects of the invention, the pending styrene
moieties in alpha-olefin/divinylbenzene copolymers (I) serve as
monomer, initiator, and chain transfer units in a subsequent graft
reaction with other olefinic monomers. The graft reactions include
graft-from, graft-onto, and graft-through processes. The pendant
styrene moieties, resemble a styrene monomer in that they are very
reactive in many chain polymerization reactions, including free
radical, cationic, anionic and transition metal coordination
polymerization reactions. In the presence of olefinic monomers,
alpha-olefin/divinylbenzene copolymers (I) and catalyst, a graft
polymerization reaction takes place involving the pendant styrene
groups in the alpha-olefin/divinylbenzene copolymer to form the
graft copolymer (II). Most graft reactions take place in
homogeneous solution or finely dispersed slurry solution.
[0052] In the case of an anionic graft reaction, the preferred
process involves the conversion of pendant styrene groups to living
anionic initiators, which would begin with a metallation reaction
of copolymer (I) with alkyllithium (such as n-BuLi) to form a
polyolefin containing pendant benzylic anions, as illustrated
below. 11
[0053] By limiting the amount of alkyllithium added to the reaction
to an amount less than would be required to react with all of the
divinylbenzene units in the copolymer (I), the metallation reaction
between styrene and alkyllithium will be quantitative. In other
words, no purification will be needed before adding an
anion-polymerizable monomer to continue the living anionic
graft-from polymerization process. Preferred anion-polymerizable
monomers include, for example, vinyl aromatic compounds, such as
styrene and alkyl substituted styrene, acrylamides, alkyl acrylates
and methacrylates, and conjugated dienes, such as isoprene and
butadiene, and their mixtures. With the coexistence of polymeric
anions and monomers susceptible to anionic polymerization, living
anionic polymerization takes place, as is described, for example,
by R. Milkovich et al in U.S. Pat. No. 3,786,116. It is important
to note that the anionic polymerization of various monomers, such
as methyl methacrylate, can take place at room temperature without
causing any detectable side reactions, which may be associated with
the stable benzylic anion initiator. After achieving the desired
composition of the graft copolymer, the graft-from reaction can be
terminated by adding a proton source, e.g., an alcohol such as
methanol or isopropanol, or other conventional polymerization
terminator to the reaction mass. In addition, the living anionic
chain ends can be converted to a variety of functional groups by
controlled termination reactions using any of a number of
electrophiles, including ethylene oxide, propylene oxide,
episulfides and carbon dioxide, before adding the proton source.
The termination reactions are very effective at room temperature.
However, a slight molar excess of the terminating agent usually is
used to assure complete termination of the polymerization reaction.
A wide range of polymers, including random and block copolymers,
with well-defined molecular weight and narrow molecular weight
distribution, can be prepared by anionic polymerization. Thus, by
using this easily controllable living graft-from reaction
technique, a variety of graft copolymer compositions with
well-defined side chain segments have been produced.
[0054] In the transition metal coordination graft reaction process,
the pendant styrene units in the alpha-olefin/divinylbenzene
copolymers (I) serve not only as monomers in the graft-through
reactions but also as chain transfer agents in the graft-onto
reactions as illustrated below. 12
[0055] After mixing the copolymer (I) and an olefin monomer with or
without hydrogen in a suitable diluent, the transition metal
coordination catalyst is then introduced to initiate graft-through
or/and graft-onto polymerization reactions. Olefin monomers that
may be used include, for example, aliphatic alpha-olefins, aromatic
vinyl compounds, cyclic olefins, and their mixtures having 2 to 15
carbon atoms. Suitable aliphatic alpha-olefins include, for
example, ethylene, 1-propene, 1-butene, 1-hexene, 1-octene,
4-methyl-1-pentene, and so on. Suitable aromatic vinyl compounds
include, for example, styrene and styrene derivatives, such as
p-methylstyrene, p-chlorostyrene or the like. Suitable cyclic
olefins include, for example, norbornene and norbornene
derivatives, such as 1-methylnorbornene, 5-methylnorbornene,
5,6-dimethylnorbornene or the like. Suitable diluents include the
general group of aliphatic and aromatic hydrocarbons, used singly
or in a mixture, such as propane, butane, pentane, cyclopentane,
hexane, toluene, heptane, isooctane or the like.
[0056] The transition metal coordination catalysts capable of
olefin polymerization may be used for the graft reaction. Catalysts
of this type include the active ionic complex shown in the
following formula: 13
[0057] wherein L is a ligand such as cyclopentadienyl, substituted
cyclopentadienyl, amido, phosphido, a bulky alpha-diimine group or
the like, or a bridged ligand having a covalent bridging group
(such as silane, methyl and dimethyl groups) between two ligands; X
is selected from hydride, halo, alkyl, aryl, aryloxy, and alkoxy; m
and n, independently, are 0, 1 or 2; R.sup.1 is a hydride or
hydrocarbon having from 1 to 20 carbon atoms; and p is 1 or 2. M is
a transition metal of Groups IIIB to VIIB and VIII of the Periodic
Table. Particularly suitable catalysts are metallocene complexes of
a Group IVB and VB metal such as titanium, zirconium and hafnium.
A.sup.- is a non-coordinating, compatible anion. Particularly
suitable anions are those derived from methylaluminoxane (MAO) and
borates, such as tetra(pentafluorophenyl)bora- te and
methyltri(pentafluorophenyl)borate. The ionic catalyst species
useful in the invention may be prepared by methods known in the
art. For example, they may be prepared by combining (a) a
transition metal compound of the Groups IIIB to VIIB and VIII of
the Periodic Table and (b) a compound capable of reacting with a
transition metal compound to form an ionic complex. In the reaction
of compounds (a) and (b), the compound (a) forms a cation formally
having a coordination number that is one less than its valence, and
the compound (b) becomes a non-coordinating, compatible anion.
[0058] The graft polymerization processes of the present invention
can be carried out under homogeneous or suspension solution
conditions, depending on the copolymer (I) and olefin monomer
used.
[0059] The hydrogen gas provides a vital role in the graft-onto
reactions, especially using iso-specific metallocene catalysts
(such as rac-SiMe.sub.2[2-Me-4-Ph(Ind)].sub.2ZrCl.sub.2/MAO
complex) that engages the polymerization of propylene and styrene
with 1,2- and 2,1-insertion modes, respectively. The detailed
reaction mechanism is illustrated below. 14
[0060] During the polymerization of propylene (with 1,2-insertion
manner) the propagation Zr--C site (I') can also react with the
pendant styrene unit (with 2, 1-insertion manner) in the copolymer
(I) to form a dormant propagating site (II'). Although the
catalytic Zr--C site in compound (II') becomes inactive to both
propylene and styrene, due to a steric jamming during the
consecutive insertion of 2,1-inserted styrene and 1,2-inserted
propylene (see Chung et al, J. Polym. Sci. Polym Chem., 37, 2795,
1999), the dormant Zr--C site (II') can react with hydrogen to form
the desirable graft copolymer (II) and regenerate a Zr--H species
that is capable of reinitiating the polymerization of propylene and
of continuing the polymerization cycles. The molecular weight of PP
graft is linearly proportional to the molar ratio of
[propylene]/[pendant styrene units], and basically independent of
the [propylene]/[hydrogen]. However, hydrogen is crucial to
maintain high catalyst activity.
[0061] In the free radical graft reaction process, the pendant
styrene units in the alpha-olefin/divinylbenzene copolymer (I)
serve as monomers directly. After mixing the copolymer (I) with the
free radical polymerizable alpha-olefin monomer in a suitable
diluent, the free radical initiator is introduced to initiate
graft-onto or/and graft-through polymerization reactor under
conditions effective to form free radicals. As the radical
polymerizable monomer to be used in this graft reaction, those well
known in the art can be used. Specific examples of suitable
monomers include methyl methacrylate, ethyl methacrylate, butyl
methacrylate, octyl methacylate, methacrylic acid, methyl acrylate,
ethyl acrylate, butyl acrylate, octyl acrylate, 2-hydroxyethyl
acrylate, glycidyl acrylate, acrylic acid, maleic anhydride, vinyl
acetate, acrylonitrile, acrylamide, vinyl chloride, vinyl fluoride,
vinylidenedifluoride, tertrafluoroethylene, styrene, alpha-methyl
styrene, trimethoxyvinylsilane, triethoxyvinylsilane and so on.
These radical polymerizable monomers can be used either singly or
as a combination of two or more monomers.
[0062] In a thermal initiation process, the reaction temperature
may be in the range of 50 to 250.degree. C., preferably in the
range of from 65 to 120.degree. C. The polymerization time
typically is in the range of from about 10 minutes to about 30
hours, and preferably from about 1 to 15 hours.
[0063] The following examples are illustrative of the
invention.
EXAMPLE 1
Synthesis of Poly(ethylene-ter-1-octene-ter-divinylbenzene) by
Et(Ind)2ZrCl.sub.2/MAO Catalyst
[0064] In a terpolymerization reaction, 1-octene (80 mmol) and
divinylbenzene (20 mmol) were mixed with 100 ml of hexane and 3 ml
of methylaluminoxane (MAO) (2.5 M in toluene) in a sealed Parr 450
mL stainless autoclave equipped with a mechanical stirrer. The
sealed reactor was then saturated with 10 psi ethylene gas at
50.degree. C. before adding an ethyldiindenylzirconium dichloride
catalyst solution (Et(Ind).sub.2ZrCl.sub.2 (2.5 .mu.mol) in
toluene) to initiate the polymerization. Additional ethylene was
fed continuously into the reactor by maintaining a constant
pressure (10 psi) during the entire course of the polymerization.
After 30 minutes, the reaction was terminated by adding 100 mL of
dilute HCl solution in methanol. The polymer was precipitated in
methanol and isolated by filtration. Further purification was
carried out by redissolving the polymer in hexane and
reprecipitating it in methanol twice. After vacuum drying for 8 h,
3.79 g of ethylene/1-octene/divinylbenzene terpolymer were
obtained. The terpolymer was completely soluble in common organic
solvents, such as hexane, toluene and tetrahydrofuran (THF). The
terpolymer composition (69.4 mol % ethylene, 28.6 mol % 1-octene,
and 2.0 mol % DVB) and molecular weight (Mw=92,900 and Mn=43,300)
were analyzed by .sup.1H NMR and gel permeation chromatography
(GPC), respectively. The mole ratio of unsaturation/divinylbenzene
moieties (TUS/DOU) is near unity. The glass transition temperature
of the terpolymer (Tg=-57.degree. C.), was measured by differential
scanning calorimetry (DSC). The sharp Tg transition with flat
baseline indicates homogeneous terpolymer microstructure.
EXAMPLES 2-7
Synthesis of Poly(ethylene-ter-1-octene-ter-divinylbenzene) by
Et(Ind).sub.2ZrCl.sub.2/MAO Catalyst
[0065] In a series of Examples, high molecular weight of linear
ethylene/1-octene/divinylbenzene copolymers were prepared in
accordance with the procedures described in Example 1. The monomer
feed for each example is indicated in Table 1 (Table 1 also shows
the results for Example 1, as well as an un-numbered example for an
ethylene-1-octene copolymer). The composition and molecular weight
(and molecular weight distribution) of terpolymer were determinated
by .sup.1H NMR and gel permeation chromatography (GPC),
respectively. The glass transition temperature (Tg) was measured by
differential scanning calorimetry (DSC). The results obtained are
set forth in Table 1. All terpolymerization reactions of
ethylene/1-octene/divinylbenzene were very effective when using
Et(Ind).sub.2ZrCl.sub.2/MAO catalyst. A broad composisition range
of terpolymers was obtained with high molecular weight, and narrow
molecular weight distribution. In general, the terpolymers exhibit
a mole ratio of TUS/DOU near unity and a low Tg (<-40.degree.
C.) in a wide range of copolymer compositions, even those having
relatively high divinylbenzene contents (e.g., 8 mole %).
1TABLE 1 A summary of terpolymerization.sup.a) of ethylene,
1-octene and divinylbenzene using rac- Et(Ind).sub.2ZrCl.sub.2/MAO
catalyst Monomer concn. in the copolymer composition.sup.b) feed
mol/l mol % C.sub.2H.sub.2 Divinyl Cat. Activity TUS/ Tg, Ex. Psi
1-Octene benzene KgP/molZr.h [E] [O] [D] DOU .degree. C. Mw PD 10
0.8 0 7776 61.5 38.5 0 -- -60.2 79286 1.97 1 10 0.8 0.2 3032 69.4
28.6 2.0 0.99 -57.4 92861 2.15 2 10 0.8 0.4 2016 66.8 29.2 4.0 0.95
-53.5 92441 2.28 3 1 0.8 0.8 1840 74.8 20.8 4.4 0.98 -51.2 36871
2.59 4 5 0.8 0.2 1224 64.4 33.4 2.2 0.92 -60.3 51576 2.16 5 5 0.8
0.8 1128 63.8 29.5 6.7 0.92 -56.5 58864 2.51 6 5 0.8 1.4 1000 69.8
22.2 8.0 0.96 -50.3 71505 2.27 7 5 0.4 0.8 1309 71.8 20.9 7.3 0.92
-55.0 68780. 2.07 .sup.a)Polymerization conditions: [cat] = 2.5
.times. 10.sup.-6 mol, [MAO]/[Zr] = 3000; solvent: 100 ml hexane;
polymerization temperature: 50.degree. C.; polymerization time: 30
min; .sup.b)[E]: Ethylene; [O]: 1-Octene; [D]: Divinylbenzene;
TUS/DOU: mole ratio of unsaturation/divinylbenzene.
EXAMPLES 8-11
Synthesis of Poly(ethylene-ter-1-octene-ter-divinylbenzene) by
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.2/MAO Catalyst
[0066] In a series of Examples, ethylene, 1-octene and
divinylbenzene were terpolymerized in the presence of a catalyst
system consisting of dicyclopentadienyldimethylsilyl-t-butyl
aminotitanium dichloride/methylaluminoxane
([C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCI.- sub.2/MAO). The
reaction procedures described in Example 1 were followed by adding
1-octene, divinylbenzene, hexane and methylaluminoxane (MAO) into a
Parr 450 ml stainless autoclave reactor. Ethylene gas was then
connected to the reactor. After saturating with ethylene gas at
50.degree. C., the polymerization reaction was initiated by
charging [C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.2 (2.5
.mu.mol) in toluene solution into the monomer mixture. Table 2
summarizes the reaction conditions and results. Some terpolymers
produced were not completely soluble. The soluble portions were
analyzed by .sup.1H NMR and DSC. In general, the
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiC.sub.2MAO catalyst showed
good divinylbenzene incorporation in the terpolymer, even up to 26
mole % divinylbenzene content. However, the mole ratio of
unsaturation/divinylbenzene moieties (TUS/DOU) in each copolymer
was well-below unity, indicating some secondary reaction having
occurred at the pendant styrene groups in the copolymer.
2TABLE 2 A summary of terpolymerization.sup.a) of ethylene,
1-octene and divinylbenzene using
[(C.sub.5Me.sub.4)SiMe.sub.2N(tBu)]TiCl.sub.2/MAO catalyst monomer
concn. in the feed copolymer composition.sup.c) mol/l mol %
Ethylene Divinyl- Cat. Activity TUS/ Tg Examples psi 1-Octene
benzene KgP/molZr.h [e] [O] [D] DOU .degree. C. 8 10 0.8 0 2880
17.8 82.2 0 -- -61.3 9 10 0.8 0.2 1504 14.6 78.2 7.2 0.58 -58.5 10
10 0.8 0.4 984 25.6 58.3 16.1 0.68 -55.9 11 10 0.8 0.8 536 31.0
41.2 26.8 0.52 -46.2.sup.b) .sup.a)Polymerization conditions: [cat]
= 2.5 .times. 10.sup.-6 mol, [MAO]/[Ti] = 3000; solvent: 100 ml
hexane; polymerization temperature: 50.degree. C.; polymerization
time: 30 min; .sup.b)Crystallinity exists; .sup.c)[E]: Ethylene;
[O]: 1-Octene; [D]: Divinylbenzene; TUS/DOU: mole ratio of
unsaturation/divinylbenzene.
EXAMPLES 12-15
Synthesis of Poly(ethylene-ter-1-octene-ter-divinylbenzene) by
CP.sub.2ZrCl.sub.2/MAO Catalyst
[0067] Another series of Examples was conducted to evaluate the
terpolymerization of ethylene, 1-octene and divinylbenzene in the
presence of dicyclopentadienylzirconium
dichloride/methylaluminoxane catalyst (CP.sub.2ZrCl.sub.2/MAO) by
the reaction procedures described in Example 1. The terpolymers
produced were not completely soluble. The soluble portions were
analyzed by .sup.1H NMR and DSC. Table 3 summarizes the reaction
conditions and results. In general, all reactions conducted in the
presence of CP.sub.2ZrCl.sub.2/MAO catalyst showed poor
divinylbenzene incorporation, with TUS/DOU ratios well-below unity.
DSC results showed some detectable melting peaks in each
terpolymer, indicating an inhomogneous composition
distribution.
3TABLE 3 A summary of terpolymerization.sup.a) of ethylene,
1-octene and divinylbenzene using Cp.sub.2ZrCl.sub.2/MAO catalyst
Monomer concn. in the feed, mol/l Di- Cat. copolymer
composition,.sup.c) Ethy- vinyl Activity mol % lene 1-Oc- ben-
KgP/mol TUS/ Tg, Ex. Psi tene zene Zr.h [E] [O] [D] DOU .degree. C.
12 10 0.8 0 3968 77.5 22.5 0 -- -52.4.sup.b) 13 10 0.8 0.2 2296
78.1 20.8 1.1 0.52 -52.2.sup.b) 14 10 0.8 0.6 1328 83.6 14.9 1.5
0.51 -43.0.sup.b) 15 10 0.8 1.2 760 81.3 15.1 3.6 0.24 -28.1.sup.b)
.sup.a)Polymerization conditions: [cat] = 2.5 .times. 10.sup.-6
mol, [MAO]/[Zr] = 3000; solvent: 100 ml hexane; polymerization
temperature: 50.degree. C.; polymerization time: 30 min;
.sup.b)Crystallinity exists; .sup.c)[E]: Ethylene; [O]: 1-Octene;
[D]: Divinylbenzene; TUS/DOU: mole ratio of
unsaturation/divinylbenzene.
EXAMPLE 16
Synthesis of Poly(ethylene-ter-propylene-ter-divinylbenzene) by
Et(Ind).sub.2ZrCl.sub.2/MAO Catalyst
[0068] In a terpolymerization reaction, divinylbenzene (10 mmol)
was added into a Parr 450 ml stainless autoclave reactor with
hexane (100 ml) and methylaluminoxane (3 ml, 2.5 M in toluene).
Pre-mixed ethylene (40 psi) and propylene (60 psi) were then
connected to the reactor. After saturating with both ethylene and
propylene gases at 50.degree. C., the total pressure in the reactor
was controlled at 30 psi. The polymerization reaction was initiated
by charging a Et(Ind).sub.2ZrCl.sub.2 (2.5 .mu.mol) in toluene
solution into the monomer mixture. A constant, mixed
ethylene/propylene pressure was maintained throughout the
polymerization process. To assure a constant comonomer ratio, the
polymerization was terminated within 15 minutes by adding dilute
HCl/methanol solution. The polymer was isolated by filtration and
was washed completely with methanol and dried under vacuum for 8 h.
About 1.74 g of terpolymer was obtained, which was completely
soluble in common organic solvents, such as hexane, toluene and
tetrahydrofuran (THF). The terpolymer was analyzed by .sup.1H NMR,
GPC and DSC. The .sup.1H NMR results showed that the terpolymer
contained 56.4 mole % of ethylene, 42.5 mole % of propylene and 1.1
mole % of divinylbenzene, and the mole ratio of TUS/DOU was near
unity. The GPC curve showed a high molecular weight terpolymer
having a narrow molecular weight distribution. A sharp glass
transition temperature (Tg) at -50.degree. C., without any
detectable melting peak, in the DSC curve indicated that the
terpolymer had a narrow composition distribution.
EXAMPLES 17-21
Synthesis of Poly(ethylene-ter-propylene-ter-divinylbenzene) by
Et(Ind).sub.2ZrCl.sub.2/MAO Catalyst
[0069] In a series of Examples, high molecular weight
ethylene/propylene/divinylbenzene terpolymers were prepared by the
reaction procedures described in Example 16, except for the monomer
feeds, which are shown in Table 4. In general, the incorporation of
divinylbenzene in the ethylene-propylene-divinylbenzene terpolymer
was effective when using Et(Ind).sub.2ZrCl.sub.2 catalyst. Up to 20
mole % of divinylbenzene was observed in the terpolymers. All
terpolymers produced were soluble in common organic solvents and
were analyzed by .sup.1H NMR, GPC and DSC. Each terpolymer
exhibited a mole ratio of TUS/DOU near unity. The DSC results
showed no detectable melting point (Tm) in the terpolymers. The
sharp glass transition temperature (Tg) with flat baseline in each
DSC curve indicated homogeneous terpolymer microstructures.
4TABLE 4 A summary of terpolymerization of ethylene, propylene and
divinylbenzene by rac-Et(Ind).sub.2ZrCl.su- b.2/MAO catalyst.sup.a)
Catalyst Copolymer E/p Activi- composition,.sup.b) Mixing Divinyl
ty kg Mol % Ratio benzene P/mol TUS/ Tg Ex. psi/psi mol/l Zr.h [E]
[P] [D] DOU .degree. C. Mw Mn PD 16 40/60 0.1 2780 56.4 42.5 1.1
94.0 -50.6 85623 39277 2.18 17 40/60 0.3 2000 59.3 39.0 1.7 91.2
-47.3 96554 47564 2.03 18 40/60 0.6 1650 62.4 32.9 4.7 96.0 -31.3
98158 41769 2.35 19 40/60 1.2 1230 56.0 22.9 21.1 96.0 -21.6 137480
63355 2.17 20 60/40 0.3 1810 67.8 30.6 1.6 96.0 -36.4 102503 49759
2.06 21 60/40 0.6 1700 65.3 30.3 4.4 90.2 -29.0 127861 56827 2.25
.sup.a)Polymerization conditions: 100 ml hexane, [Zr] = 2.5 .times.
10.sup.-6 mol, [MAO]/[Zr] = 3000, 50.degree. C., 15 minutes, 30
psi; .sup.b)[E]: Ethylene; [P]: Propylene; [D]: Divinylbenzene;
TUS/DOU: mole ratio of unsaturation/divinylbenzene.
EXAMPLES 22-24
Synthesis of Poly(ethylene-ter-propylene-ter-divinylbenzene) by
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.2/MAO Catalyst
[0070] A series of Examples was conducted to evaluate the
terpolymerization of ethylene, propylene and divinylbenzene using
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.2/MAO catalyst. The
reaction procedures described in Example 16 were followed by adding
divinylbenzene, hexane and methylaluminoxane (MAO) into a Parr 450
ml stainless autoclave reactor. Pre-mixed ethylene/propylene gases
were then connected to the reactor. After saturating with both
ethylene and propylene gases at 50.degree. C., the total pressure
in the reactor was controlled at 30 psi. The polymerization
reaction was initiated by charging a
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.2 (2.5 .mu.mol) in
toluene solution into the monomer mixture. Table 5 summarizes the
reaction conditions and results. In general, the incorporation of
divinylbenzene in the ethylene-propylene-divinylbenzene terpolymer
was very effective when using
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.- 2/MAO catalyst.
However, most of the terpolymers produced were not completely
soluble. Some insoluble gel particles, which are indicative of a
degree of crosslinking, were observed. The terpolymers were
analyzed by .sup.1H NMR, GPC and DSC. The DSC curve for each
terpolymer indicated no clear thermal transition with an uneven
baseline.
5TABLE 5 A summary of terpolymerization of ethylene, propylene and
divinylbenzene by [(C.sub.5Me.sub.4)SiMe.s-
ub.2N(t-Bu)]TiCl.sub.2/MAO catalyst.sup.a) E/P mix- Di- ing vinyl-
Catalyst ratio ben- Activity Copolymer composition,.sup.b) psi/
zene kg Mol % Tg Ex. psi mol/l P/mol Ti.h [E] [P] [D] TUS/DOU
.degree. C. 22 50/50 0.1 453 48.6 44.8 6.6 0.42 n.d..sup.b) 23
50/50 0.3 400 48.8 37.1 14.1 0.44 n.d. 24 50/50 0.6 421 41.3 28.8
29.9 0.52 n.d. .sup.a)Polymerization conditions: 100 ml hexane,
[Ti] = 2.5 .times. 10.sup.-6 mol, [MAO]/[Ti] = 3000, 50.degree. C.,
15 minutes 30 psi; .sup.b)n.d. - cannot be determined; .sup.c)[E]:
Ethylene; [P]: Propylene; [D]: Divinylbenzene; TUS/DOU: mole ratio
of unsaturation/divinylbenzene.
EXAMPLES 25-33
Synthesis of Poly(ethylene-co-divinylbenzene) by
Et(Ind).sub.2ZrCl.sub.2/M- AO Catalyst
[0071] In a series of Examples, high molecular weight of
ethylene/divinylbenzene copolymers were prepared by batch slurry
polymerization in a Parr 450 ml stainless autoclave equipped with a
mechanical stirrer. After mixing the desired quantities of
divinylbenzene, MAO and hexane in a reactor, the reactor was sealed
and then saturated with ethylene gas at 50.degree. C. under the
ethylene pressure indicated in Table 6. An Et(Ind).sub.2ZrCl.sub.2
(2.5 .mu.mol) catalyst in toluene was added to initiate the
polymerization. Additional ethylene was fed continuously into the
reactor for maintaining a constant pressure during the entire
course of the polymerization. The copolymerization reactions were
terminated by adding 100 ml of dilute HCl solution in methanol. The
polymers were isolated by filtration and were washed completely
with methanol and dried under vacuum for 8 hrs. The results
obtained are set forth in Table 6.
[0072] In general, the incorporation of divinylbenzene in
polyethylene was effective when using Et(Ind).sub.2ZrCl.sub.2/MAO
catalyst. The mole ratio of TUS/DOU for each copolymer was near
unity. The relatively sharp and uniform GPC and DSC curves for all
copolymers demonstrate narrow molecular weight distributions and
substantially homogeneous composition distributions (i.e.,
compositional uniformity over the entire range of
compositions).
6TABLE 6 A summary of ethylene copolymerization with divinylbenzene
by rac-Et(Ind).sub.2ZrCl.sub.2/MAO catalyst.sup.a) Catalyst
Divinylbenzene Ethylene Divinylbenzene Activity In copolymer TUS/
Examples psi mol/l kg P/mol Zr.h mol % DOU.sup.b) 25 30 0.1 3304
0.72 0.90 26 30 0.2 2864 1.04 0.90 27 30 0.4 2456 1.97 0.92 28 30
1.2 2024 3.83 0.90 29 10 0.2 1000 2.03 0.93 30 10 0.4 984 3.26 0.96
31 10 0.8 528 5.40 0.92 32 5 0.4 640 3.82 0.91 33 5 0.8 528 6.74
0.93 .sup.a)Polymerization conditions: 100 ml hexane, [Zr] = 2.5
.times. 10.sup.-6 mol, [MAO]/[Zr] = 3000, 50.degree. C., 30 minutes
.sup.b)TUS/DOU: mole ratio of unsaturation/divinylbenzene.
EXAMPLE 34-38
Synthesis of Poly(propylene-co-divinylbenzene) by
MgCl.sub.2/TiCl.sub.4/ED- /AlEt.sub.3 Catalyst
[0073] A series of comparative polymerization reactions between
propylene and divinylbenzene were carried out using magnesium
dichloride/titanium tetrachloride/extemal donor/triethyl aluminum
(MgCl.sub.2/TiCl.sub.4/ED/A- lEt.sub.3) as a catalyst system. In a
typical Example (e.g., Example 34), 100 ml of hexane, 2.0 g of
AlEt.sub.3, and 40 mmol divinylbenzene were placed into a Parr 450
ml stainless autoclave equipped with a mechanical stirrer in an
argon filled dry-box. The reactor was sealed and then moved out
from the dry box and purged with propylene gas, and the reaction
mass was saturated with 30 psi propylene gas at 50.degree. C. About
55 mg (20.8 umol Ti) of MgCl.sub.2/ED/TiCl.sub.4 catalyst slurry in
5 ml of hexane was added under propylene pressure to initiate the
polymerization. Additional propylene was fed continuously into the
reactor to maintain a constant pressure of 30 psi during the entire
course of the polymerization. After 60 min, the reaction was
terminated by adding 100 ml of dilute HCl solution in methanol. The
polymer was isolated by filtration and was washed completely with
methanol and dried under vacuum for 8 hrs. About 6.41 g of
propylene-co-divinylbenzene was obtained. Reaction conditions
similar to those described for Example 34 were carried out for
Examples 35-38. Table 7 summarizes all experimental conditions and
results.
[0074] In general, the MgCl.sub.2/ED/TiCl.sub.4/AlEt.sub.3 catalyst
system maintained good reactivity in the presence of
divinylbenzene. As expected, divinylbenzene incorporation was very
poor, and the mole ratio of vinyl/phenyl moieties (TSU/DOU) for
each copolymer was near unity.
7TABLE 7 A summary of propylene copolymerization with
divinylbenzene by MgCl.sub.2/TiCl.sub.4--AlEt.sub.3/ED
catalyst.sup.a) Divinyl- Catalyst Divinylbenzene Propylene benzene
Activity in copolymer TUS/ Ex. Psi mol/l kg P/mol Ti. h mol %
DOU.sup.b) 34 30 0.4 308 0.59 0.85 35 30 0.8 217 0.94 0.94 36 30
1.2 68 -- -- 37 50 0.8 318 0.62 0.90 38 70 0.8 392 0.51 0.97
.sup.a)Polymerization conditions: 100 ml hexane, [Ti] = 20.8 umol,
Al/Ti = 90, ED/Ti= 6, 50.degree. C., 60 minutes. .sup.b)TUS/DOU:
mole ratio of unsaturation/divinylbenzene.
EXAMPLE 39
Lithiation and Silylation reactions of
Poly(ethylene-ter-1-octene-ter-divi- nylbenzene)
[0075] In an argon filled dry box, 0.86 g of
poly(ethylene-ter-1-octene-te- r-divinylbenzene) containing 4.7
mole % of divinylbenzene units was dissolved in 100 ml of anhydrous
cyclohexane in a 250 ml air-free flask equipped with a magnetic
stirrer bar. Next, 0.75 mmol of s-butyl lithium (s-BuLi) solution
and 0.75 mmol of tetrarnethylethylenediamine (TMEDA) were added
into the flask, and the resulting solution was stirred at ambient
temperature for 3 hours before adding 5 ml of trimethylsilane
chloride (Me.sub.3SiCl). After reacting for 1 hour at room
temperature, the silylated polymer was isolated by precipitation in
methanol. Repeated washing with methanol was performed before
drying the resulting polymer under vacuum. .sup.1H NMR spectrum
shows no peak corresponding to a vinyl group and a strong peak at
0.05 ppm, corresponding to the methyl proton next to Si. Both
metallation and silylation efficiencies were almost 100%.
EXAMPLE 40
Maleation Reaction of
Poly(ethylene-ter-1-octene-ter-divinylbenzene)
[0076] In a 250 ml flask equipped with a stirrer and a condenser,
0.8 g of poly(ethylene-ter-1-octene-ter-divinylbenzene) containing
4.7 mole % of divinylbenzene was dissolved in 140 ml of xylene,
along with 5 g of maleic anhydride and 0.1 g of free radical
inhibitor. Under a nitrogen atmosphere, the solution was heated to
140.degree. C. for 5 hours. A maleated polymer was isolated by
precipitation in isopropanol. Repeated washing with isopropanol and
acetone were performed before drying the resulting polymer under
vacuum. IR spectrum analysis indicated a strong anhydride (C.dbd.O)
absorption band with an intensity indicating 11.5 wt % maleic
anhydride in the polymer.
EXAMPLES 41-44
Anionic Graft Reactions of
Poly(ethylene-ter-1-octene-ter-divinylbenzene)
[0077] In a series of Examples, the indicated quantity (shown in
Table 8) of poly(ethylene-ter-1-octene-ter-divinylbenzene)
containing 4.7 mole % of divinylbenzene was dissolved in 100 ml of
anhydrous cyclohexane in a 250 ml flask equipped with a stirrer. A
metallation reaction was performed by adding the indicated
quantities (shown in Table 8) of s-BuLi and
tetramethylethylenediamine (TMEDA) to the solution. In each case,
the resulting mixture was stirred at ambient temperature for 3
hours before adding styrene monomer. An anionic graft-from reaction
was then carried out at ambient temperature for 1 hour before
adding 10 ml of isopropanol to terminate the reaction. The
precipitated polymers were filtered and then subjected to
fractionation. The graft copolymer structures and compositions were
determined by IR, .sup.1H NMR, GPC and DSC studies. Table 8
summarizes the reaction conditions and the experimental results.
Overall, the graft-from reactions were very effective, with more
than 80% monomer conversion within one hour. The graft content
increased proportionally with increasing monomer concentration and
reaction time. Since the graft-from reaction involves a living
anionic polymerization, it is reasonable to assume that each
benzylic lithium produces one polymer side chain and each side
chain has a similar molecular weight. The graft density, defined as
the number of grafted side chains per 1000 carbons in the polymer
backbone, is the same as the density of benzylic anions. The side
chain length is basically proportional to the reaction time and
monomer concentration.
8TABLE 8 A summary of graft polymerization of styrene from
"reactive" poly(ethylene-ter-1-octene-ter-divinylbenz- ene)
terpolymer Graft copolymers Reaction conditions.sup.a) Graft
density Sec- Graft # of graft/ Graft Terpolymer.sup.b) BuLi TMEDA
Styrene Yield composition 1000 C length Ex. G mmol mmol ml g mol %
of backbone 10.sup.3 g/mol 41 0.85 0.60 0.60 1.0 1.83 39.4 19 1.69
42 0.81 0.60 0.60 2.2 2.27 47.9 19 2.40 43 0.81 0.60 0.60 3.5 3.21
57.7 19 4.64 44 0.85 0.75 0.75 3.5 3.23 59.7 24 3.26
.sup.a)Solvent: 100 ml of anhydrous cyclohexane; Metallation
reaction time: 3 h; Graft from polymerization time: 1 h; Reaction
temperature: 25.degree. C. .sup.b)The starting material was
poly(ethylene-ter-1-octene-ter-divinylbenzene) terpolymer with
styrenic double bond content of 4.7 mol %.
EXAMPLES 45-47
Graft Reactions of Poly(ethylene-ter-propylene-ter-divinylbenzene)
with Styrene, p-Methylstyrene), and MMA by Living Anionic
Polymerization
[0078] In a 250 ml flask equipped with a stirrer, 3 g of
poly(ethylene-ter-propylene-ter-dicinylbenzene) containing 50.1 mol
% ethylene, 47.0 mol % propylene, and 2.9 mole % of divinylbenzene
was dissolved in 100 ml of anhydrous cyclohexane. The metallation
reaction was taken place by adding 2 ml of 2.5 M n-BuLi/hexane to
the solution. The mixture was stirred at ambient temperature for 3
hours before adding desirable quantity of monomer (shown in Table
9). The graft reaction was then carried out at ambient temperature
for the indicated period before adding 10 ml of isopropanol to
terminate the anionic graft reaction. The precipitated polymer was
filtered and then subjected to Soxlet fractionation by hexane. In
each case, it was found that less than 5 weight % of the copolymer
was ungrafted. The graft copolymer structures and compositions were
determined by .sup.1H NMR, GPC and DSC studies. Table 9 summarizes
the reaction conditions and the experimental results. Overall, the
graft-from reactions with styrene, p-methylstyrene (p-MS) and
methylmethacrylate (MMA) were very effective with high
incorporation of side chain polymers.
9TABLE 9 A summary of anionic graft polymerization of styrene,
p-methylstyrene and methylmethacrylate from
Poly(ethylene-ter-propylene-ter- divinylbenzene) terpolymer Graft
Polym. Conditions Graft Comp., wt. % Time Hexane soluble PS or
P(PMS) Ex. Monomer/g hr Yield, g. Portion, wt. % EP-DVB or PMMA 45
Styrene/4.5 4.0 7.1 4.2 39.7 PS/60.3 46 p-MS/4.1 4.0 6.7 3.6 42.8
P(PMS)/57.2 47 MMA/5.4 16.0 8.1 4.1 34.3 PMMA/65.7
EXAMPLE 48
Lithiation and Silylation Reactions of
Poly(ethylene-co-divinylbenzene)
[0079] In an argon filled dry box, 8 g of
poly(ethylene-co-divinylbenzene) powder containing 1.73 mol % of
divinylbenzene units was suspended in 100 ml of anhydrous
cyclohexane in a 250 ml air-free flask with a magnetic stirrer bar.
About 6 ml of 1.3 M s-BuLi and 2.5 ml TMEDA were added to the
reactor. After allowing the lithiation reaction to take place at
60.degree. C. for 4 hours, the resulting yellow polymer powder was
filtered and washed repeatedly with hexane. About 1 g of the
lithiated polymer was then suspended in 30 ml of cyclohexane, and 3
ml of Me.sub.3SiCl was added into the slurry. The solution was then
stirred at ambient temperature for 2 hours. The silylated PE was
collected by filtering and washing repeatedly with THF, methanol,
water and then methanol before drying under vacuum. .sup.1H NMR
spectrum shows almost no peak corresponding to vinyl group and a
strong peak at 0.05 ppm corresponding to the methyl proton next to
Si. Both metallation and silylation efficiencies must be over
90%.
EXAMPLE 49
Lithiation and Silylation Reactions of
Poly(propylene-co-divinylbenzene)
[0080] In an argon filled dry box, 8 g of
poly(propylene-co-divinylbenzene- ) powder containing 0.94 mol % of
divinylbenzene units was suspended in 100 ml of anhydrous
cyclohexane in a 250 ml air-free flask with a magnetic stirrer bar.
About 6 ml of 1.3 M s-BuLi and 2.5 ml TMEDA were added to the
reactor. After allowing the lithiation reaction to take place at
70.degree. C. for 4 hours, the resulting yellow polymer powder was
filtered and washed repeatedly with hexane. About 1 g of the
lithiated polymer was then suspended in 30 ml of cyclohexane, and 3
ml of Me.sub.3SiCl was added into the slurry. The solution was then
stirred at ambient temperature for 2 hours. The silylated PP was
collected by filtering and washing repeatly with THF, methanol,
water and then methanol before drying under vacuum. .sup.1H NMR
spectrum shows almost no peak corresponding to vinyl group and a
strong peak at 0.05 ppm corresponding to the methyl proton next to
Si. Both metallation and silylation efficiencies must be over
90%.
EXAMPLES 50-56
Graft Reactions of Poly(ethylene-co-divinylbenzene) with Styrene,
p-Methylstyrene, and MMA by Living Anionic Polymerization
[0081] In a 100 ml flask equipped with a stirrer, a desirable
quantity (shown in Table 10) of the lithiated
poly(ethylene-co-divinylbenzene) prepared in Example 48 was
suspended in 30 ml of anhydrous cyclohexane. A certain quantity of
monomers (shown in Table 10) was then added to the reactor, and the
mixture was stirred at ambient temperature for the indicated period
before adding 10 ml of isopropanol to terminate the anionic graft
reaction. The precipitated polymer was filtered and then subjected
to Soxlet fractionation (using THF for styrene and p-methylstyrene
cases and acetone for MMA cases). Almost no ungrafted polymer was
observed for each example. The structures and compositions of graft
copolymers were determined by IR, .sup.1H NMR, GPC and DSC studies.
Table 10 summarizes the reaction conditions and the experimental
results.
10TABLE 10 A summary of anionic graft reaction from
poly(ethylene-co-divinylbenzene) copolymer Graft from
polymerization conditions.sup.a) Comonomer in PELi+.sup.b) Monomer
Time Yield graft Examples g g Hr g Mole % 50 1.0 Styrene/0.9 2.0
1.7 16.1 51 1.0 Styrene/2.7 4.0 3.5 41.3 52 1.0 Styrene/4.5 4.0 5.4
55.1 53 0.7 p-MS/0.9 4.0 1.5 20.4 54 0.7 p-MS/1.8 4.0 2.3 33.9 55
0.7 MMA/4.0 2.0 1.2 17.0 56 0.7 MMA/4.0 12.0 3.1 50.0
.sup.a)Polymerization conditions: 30 ml cyclohecxane as solvent,
ambient temperature .sup.b)PELi+ was prepared in Example 48
[0082] Overall, the graft-from reactions were very effective, near
quantitative styrene and p-methylstyrene conversions within 4
hours. The graft content increased proportionally with increasing
monomer concentration and reaction time. Since the graft-from
reaction involves a living anionic polymerization, it is reasonable
to assume that each benzylic lithium produces one polymer side
chain and each side chain has similar molecular weight.
EXAMPLES 57-61
Graft Reactions of Poly(propylene-co-divinylbenzene) with Styrene,
and MMA by Living Anionic Polymerization
[0083] In a 100 ml flask equipped with a stirrer, a desirable
quantity (shown in Table 11) of the lithiated
poly(propylene-co-divinylbenzene) prepared in Example 49 was
suspended in 30 ml of anhydrous cyclohexane. A certain quantity of
styrene or MMA monomers (shown in Table 11) was then added to the
reactor, and the mixture was stirred at ambient temperature for few
hours before adding 10 ml of isopropanol to terminate the anionic
graft reaction. The precipitated polymer was filtered and then
subjected to Soxlet fractionation (using THF for styrene cases and
acetone for MMA cases). No ungrafted polymer was observed in any
example. The graft copolymer structure and composition were
determined by IR, .sup.1H NMR, GPC and DSC studies. Table 11
summarizes the reaction conditions and the experimental
results.
11TABLE 11 A summary of anionic graft reaction from
poly(propylene-co-divinylbenzene) copolymer Graft from
polymerization conditions.sup.a) Comonomer in PPLi+.sup.b) Monomer
Time Yield graft Examples g g Hr g mole % 57 1.0 Styrene/0.9 1.0
1.3 10.8 58 1.0 Styrene/1.8 3.0 2.5 26.0 59 1.0 Styrene/4.5 1.0 1.9
26.4 60 1.0 Styrene/4.5 5.0 5.4 63.6 61 1.0 MMA/4.7 12.0 3.8 53.8
.sup.a)Polymerization conditions: 30 ml cyclohecxane as solvent,
ambient temperature .sup.b)PPLi+ was prepared in Example 49.
[0084] Overall, the graft-from reactions were very effective, near
quantitative styrene conversion within 5 hours. The graft content
increased proportionally with increasing monomer concentration and
reaction time. Since the graft-from reaction involves a living
anionic polymerization, it is reasonable to assume that each
benzylic lithium produces one polymer side chain and each side
chain has similar molecular weight.
EXAMPLES 62-69
Graft Copolymers of Poly(ethylene-ter-propylene-ter-divinylbenzene)
with Syndiotactic Polystyrene (s-PS) Prepared by Transition Metal
Coordination Polymerization
[0085] Under N.sub.2 atmosphere, a desirable quantity (shown in
Table 12) of poly(ethylene-ter-propylene-ter-divinylbenzene)
(EP-DVB) was dissolved in 100 ml toluene in a 250 ml flask,
equipped with a stirrer bar. Two starting EP-DVB polymers were
used, including sample EP-DVB-A (52.2 mol % ethylene, 46.5 mol %
propylene, and 1.7 mole % of divinylbenzene; Tg=-56.5.degree. C.;
Mw=85,600 and Mn=39,300 g/mol) and sample EP-DVB-B (57.5 mol %
ethylene, 39.4 mol % propylene, and 3.1 mole % of divinylbenzene;
Tg=-50.7.degree. C.; Mw=98,200 and Mn=41,800 g/mol). Styrene
monomer and MAO were then added into the polymer solution. After
stirring the homogeneous solution mixture at 50.degree. C., the
graft-onto polymerization reaction was initiated by charging
Cp*Ti(OMe).sub.3 ([MAO]/Ti=1500) catalyst. After 1 hour, 10 ml of
isopropanol was added to terminate the graft-onto reaction. The
precipitated polymer was filtered and then subjected to a
consecutive Soxlet fractionation using hexane and o-dichlorobenzene
solvents. Table 12 summarizes the experimental conditions and
results. The polymer structure and composition were determined by
.sup.1H and .sup.13C NMR, high temperature GPC and DSC studies. In
most cases, the conversion of styrene was very high, and only about
10 weight % of hexane-soluble fraction that was the ungrafted
EP-DVB terpolymer. Based on the combination of all measurements,
the o-dichlorobenzene soluble fraction was graft copolymer
(EP-DVB-g-s-PS), containing EP backbone and s-PS side chains. GPC
curve of each graft copolymer showed a single peak with a narrow
molecular distribution, and the molecular weight of graft copolymer
was much higher than that of s-PS homopolymer prepared under the
same reaction condition (without EP-DVB). In the Examples 62-66,
using a first starting EP-DVB terpolymer with 1.7 mol % DVB units,
all EP-DVB-g-s-PS graft copolymers were completely soluble in
o-dichlorobenzene at elevated temperature. In the Examples 67-69,
using a second starting EP-DVB terpolymer with 3.1 mol % DVB units,
from 2.4 weight % (Example 67) to 4.8 weight % (Example 69) of
graft copolymer was insoluble in o-dichlorobenzene.
12TABLE 12 Synthesis of Poly(ethylene-ter-propylene-
-ter-divinylbenzene)-g-s-PS graft copolymers by
Cp*Ti(OMe).sub.3/MAO Graft Graft polym. Cond. Solvent
fractionation.sup.b) composition, EP- ST wt % wt % Thermal
properties [Cat] Styrene DVB.sup.a) Yield, conv. Hexane o-DCB EP-
Tg.sub.1 Tg.sub.2 Tm Ex. umol g g g % soluble soluble Insoluble DVB
s-PS .degree. C. .degree. C. .degree. C. 62 5.0 2.7 A/0.28 2.77
91.0 7.1 93.0 0 3.1 96.9 n.d.sup.c) 99.2 271.4 63 5.0 2.7 A/0.71
3.23 92.3 12.7 87.3 0 9.9 90.1 n.d. 91.4 270.0 64 5.0 2.7 A/1.20
3.80 95.6 15.0 85.0 0 19.3 80.7 -52.1 92.3 267.1 65 10.0 2.7 A/0.52
3.12 95.0 11.0 89.0 0 6.2 93.8 n.d. 97.3 270.7 66 5.0 5.4 A/0.58
4.85 78.2 9.0 91.0 0 3.1 96.9 n.d. 98.9 272.9 67 5.0 2.7 B/0.32
2.74 88.6 5.1 92.5 2.4 6.8 93.2 -50.4 98.3 268.4 68 5.0 2.7 B/0.71
3.04 85.3 10.0 86.9 3.1 14.5 85.5 -48.1 97.6 261.5 69 5.0 2.7
B/1.20 3.51 84.5 9.9 85.3 4.8 28.6 71.4 -44.1 n.d. 256.2
.sup.a)EP-DVB-A: E: 52.2 mol %, P: 46.5 mol % and divinylbenzene:
1.7 mol %, Mw = 85623, Mn = 39277, PD = 2.18, Tg = -56.5.degree.
C., EP-DVB-B: E: 57.5 mol %, P: 39.4 mol % and divinylbenzene: 3.1
mol %, Mw = 98158, Mn = 41769, PD = 2.35, Tg = -50.7.degree. C.;
.sup.b)The polymer was first extracted by hexane for 24 hrs, and
the insoluble portion was further extracted by o-dichlorobenzene;
.sup.c)n.d.: not determined
EXAMPLE 70
Consecutive Graft Reactions of
Poly(ethylene-ter-propylene-ter-divinylbenz- ene) with Styrene and
Methylmethacrylate by Transition Metal Coordination and Living
Anionic Polymerization Processes
[0086] Most of EP-DVB-g-s-PS graft copolymers still contain some
unreacted DVB units that can be used for the subsequent living
anionic graft-from polymerization to incorporate other anionic
prepared grafted side chains. In an argon-filled drybox, 2 g of
powdery EP-DVB-g-s-PS graft copolymer (obtained from Example 69)
was dispersed in 100 ml anhydrous cyclohexane in a 250 ml flask
with a magnetic stirrer bar. After adding 1.5 mmol of s-BuLi and
1.5 mmol of TMEDA, the reaction mixture was then heated to
60.degree. C. for 1 hour. The suspension lithiated polymer powders
were filtered and repeatedly washed with hexane until the filtrate
was completely decolored. The lithiated polymer was then divided to
two parts.
[0087] One small part (about 0.5 g) was allowed to react with
Me.sub.3SiCl to determine the lithiation efficiency. The lithiated
polymer was suspended in 30 ml of cyclohexane, before adding 3 ml
of Me.sub.3SiCl. The silation reaction was allowed to take place at
room temperature with stirring for 1 hour. The resulting polymer
was filtered and washed with THF, methanol, water and then
methanol, and dried under vacuum. .sup.1H NMR result shows complete
disappearance of olefin units and a new peak at 0.05 ppm,
corresponding to methyl protons next to Si. The result clearly
showed the effective lithiation reaction of DVB units in
EP-DVB-g-s-PS graft copolymers.
[0088] The major portion of the lithiated polymer was then used for
anionic graft-from reaction, by mixing 1 g of lithiated polymer
suspended in 30 ml of cyclohexane with 5 ml of distilled MMA. The
anionic graft-from reaction was taken place at room temperature for
4 hours before terminating by adding 30 ml of methanol. The
precipitated polymer was then filtered and then subjected to
acetone extraction to remove any ungrafted PMMA homopolymer. The
amount of acetone soluble fraction was negligible. The insoluble
fraction was dried in vacuum oven to result in 1.6 g of graft
copolymer, containing EP-DVB backbone (18.4 wt %) and both s-PS
(46.1 wt %) and PMMA (35.5 wt %) side chains.
EXAMPLES 71-81
Graft Copolymers of Poly(ethylene-ter-1-octene-ter-divinylbenzene)
and Syndiotactic Polystyrene (s-PS) Prepared by Transition Metal
Coordination Polymerization
[0089] In a 250 ml flask (equipped with a magnetic stirrer bar and
under N.sub.2 atmosphere), the indicated quantity (shown in Table
13) of poly(ethylene-ter-1-octene-ter-divinylbenzene) (EO-DVB) was
dissolved in 100 ml toluene. Three starting EO-DVB elastomers were
studied to compare the effect of DVB concentration to the
graft-onto reaction, including sample EO-DVB-A (69.4 mol %
ethylene, 28.6 mol % 1-octene, and 2.0 mole % of divinylbenzene;
Tg=-57.4.degree. C.; Mw=92,800 and Mn=43,300 g/mol), sample
EO-DVB-B (66.8 mol % ethylene, 29.2 mol % 1-octene, and 4.0 mole %
of divinylbenzene; Tg=-53.5.degree. C.; Mw=92,500 and Mn=40,600
g/mol), and sample EO-DVB-C (63.8 mol % ethylene, 29.5 mol %
1-octene, and 6.7 mole % of divinylbenzene; Tg=-56.5.degree. C.;
Mw=58,900 and Mn=23,400 g/mol). Styrene monomer and MAO (with
quantities shown in Table 13) were then added into the homogeneous
polymer solution. After stirring the homogeneous solution mixture
at 50.degree. C., the graft-onto polymerization reaction was
initiated by charging Cp*Ti(OMe).sub.3 ([MAO]/Ti=1500) catalyst.
After 1 hour, 10 ml of isopropanol was added to terminate the
graft-onto reaction. The precipitated polymer was filtered and then
subjected to a consecutive Soxlet fractionation using hexane and
o-dichlorobenzene solvents. Table 13 summarizes the experimental
conditions and results. The polymer structure and composition were
determined by .sup.1H and .sup.13C NMR, high temperature GPC and
DSC studies. In most cases, the conversion of styrene was very
high, and only about 10 weight % of hexane-soluble fraction that
was the ungrafted EO-DVB terpolymer. Based on the combination of
all measurements, the o-dichlorobenzene soluble fraction was graft
copolymer (EO-DVB-g-s-PS), containing EO-DVB backbone and s-PS side
chains. The GPC curve of each graft copolymer showed a single peak
with a narrow molecular distribution, and the molecular weight of
graft copolymer was much higher than that of s-PS homopolymer
prepared under the same reaction condition (without EO-DVB). In
general, the graft efficiency increased with the concentration of
DVB units in the starting EO-DVB terpolymer. A broad composition
range of graft copolymers, with various ratios of EO-DVB/s-PS, had
been prepared. However, a small quantity of insoluble fraction was
observed in the product prepared by starting with high EO-DVB
concentration.
13TABLE 13 Synthesis of Poly(ethylene-ter-1-octene--
ter-divinylbenzene)-g-sPS graft copolymers by Cp*Ti(OMe).sub.3/MAO
catalyst Graft Solvent fractionation.sup.b) composition Graft
polym. Cond. ST wt % wt % Thermal properties [Cat] Styrene
EO-DVB.sup.a) Yield conv. Hexane o-DCB EO- Tg.sub.1 Tg.sub.2 Tm Ex.
umol g G g % Soluble soluble Insoluble DVB s-PS .degree. C.
.degree. C. .degree. C. 71 5.0 4.5 A/0.71 4.64 96.6 3.5 96.5 0 1.8
98.2 n.d..sup.c) 99.2 271.2 72 5.0 2.7 A/0.72 2.89 96.6 5.7 94.3 0
3.0 97.0 n.d. 97.8 270.7 73 5.0 0.9 A/0.72 1.10 91.0 15.3 84.7 0
10.6 89.4 -56.5 91.2 270.2 74 5.0 2.7 A/2.42 3.85 97.6 15.7 84.3 0
17.6 82.4 -52.3 92.3 267.8 75 5.0 4.5 B/0.71 4.33 79.7 4.1 93.0 2.9
4.7 95.3 n.d. 98.3 266.2 76 5.0 2.7 B/0.68 3.21 97.9 3.6 93.0 3.4
14.0 86.0 n.d. 95.2 261.3 77 5.0 0.9 B/0.71 1.35 81.0 6.0 90.0 4.0
44.0 56.0 -49.7 90.1 260.5 78 5.0 4.5 C/0.72 4.27 85.2 3.9 93.1 3.0
5.0 95.0 -50.7 97.6 263.2 79 5.0 2.7 C/0.71 2.96 88.9 4.6 91.2 4.2
13.9 86.1 -50.4 92.1 254.7 80 5.0 1.6 C/0.71 2.01 86.0 2.5 89.2 8.3
33.8 66.2 -48.1 n.d. n.d. 81 5.0 1.3 C/1.28 2.04 84.0 11.5 80.0 8.5
43.8 56.2 -44.1 n.d. n.d. .sup.a)EO-DVB-A: E: 69.4 mol %, O: 28.6
mol % and divinylbenzene: 2.0 mol %, Mw = 92861, Mn = 43231, PD =
2.15, Tg = 57.4.degree. C.; EO-DVB-B E: 66.8 mol %, O: 29.2 mol %
and divinylbenzene: 4.0 mol %, Mw = 92440, Mn = 40612, PD = 2.28,
Tg = -53.5.degree. C.; EO-DVB-C: E: 63.8 mol %, O: 29.5 mol % and
divinylbenzene: 6.7 mol %, Mw = 58864, Mn = 23412, PD = 2.51, Tg =
-56.5.degree. C.; .sup.b)The polymer was first extracted by hexane
for 24 hrs, and the insoluble portion was further extracted by
o-dichlorobenzene; .sup.c)n.d.: not determined
EXAMPLES 82-88
Graft Copolymers of Poly(ethylene-ter-propylene-ter-divinylbenzene)
with Polyethylene Prepared by Transition Metal Coordination
Polymerization
[0090] Two starting poly(ethylene-ter-propylene-ter-divinylbenzene)
(EP-DVB) polymers were studied to understand the effect of DVB
concentration on the graft reaction, including sample EP-DVB-A
(52.2 mol % ethylene, 46.5 mol % propylene, and 1.7 mole % of DVB;
Tg=-56.5.degree. C.; Mw=85,600 and Mn=39,300 g/mol) and sample
EP-DVB-B (57.5 mol % ethylene, 39.4 mol % propylene, and 3.1 mole %
of divinylbenzene; Tg=-50.7.degree. C.; Mw=98,200 and Mn=41,800
g/mol). In a 450 ml Parr autoclave equipped with a mechanical
stirrer and N.sub.2 atmosphere, a desirable quantity (shown in
Table 14) of EP-DVB was dissolved in 100 ml toluene. After adding
MAO to the polymer solution, the sealed reactor was then saturated
with 30 psi ethylene pressure and increased the temperature to
50.degree. C. The [C.sub.5Me.sub.4(SiMe.sub.2NtBu)]TiCl.su- b.2
(1.5 umol; [MAO]/[Ti]=1500) catalyst in toluene was then added to
initiate the polymerization. Additional ethylene was fed
continuously into the reactor by maintaining a constant pressure
(30 psi) during the whole course of the polymerization. After 1
hour, 10 ml of isopropanol was added to terminate the graft-onto
reaction. The precipitated polymer was filtered and then subjected
to a consecutive Soxlet fractionation using pentane and xylene
solvents. Table 14 summarizes the experimental conditions and
results. The polymer structure and composition were determined by
.sup.1H NMR, high temperature GPC and DSC studies. In most cases,
the incorporation of ethylene was very high, and only few weight %
of pentane-soluble fraction that was the ungrafted EP-DVB
terpolymer. The rest of polymer was soluble in hot xylene, which
was EP-DVB-g-PE graft copolymer. There was almost no insoluble
fraction
14TABLE 14 Synthesis of Poly(ethylene-ter-propylene-
-ter-divinylbenzene)-g-PE graft copolymer by
[C.sub.5Me.sub.4(SiMe.sub.2NtBu)]TiCl.sub.2/MAO catalyst Graft
Solvent fractionation.sup.b) composition Thermal Graft polym. Cond.
wt % wt % properties Ethylene EP-DVB.sup.a) Yield Pentane Xylene
EP- Tg Tm Ex. psi g g soluble soluble Insoluble DVB PE .degree. C.
.degree. C. 82 30 A/0.35 6.2 4.0 96.0 0 2.3 97.7 -57.0 131.0 83 30
A/0.76 5.8 6.7 93.3 0 7.0 93.0 -56.0 131.3 84 30 A/1.25 5.5 8.8
89.7 n.d..sup.c) 13.7 86.3 -57.8 128.5 85 30 B 0.41 7.1 1.6 98.4 0
4.4 95.6 -51.3 130.1 86 30 B/0.80 4.9 3.3 96.7 n.d. 13.8 86.2 -51.5
126.4 87 30 B/1.24 4.5 3.8 94.6 1.6 25.0 75.0 -50.9 124.5 88 30
B/2.44 4.3 4.0 93.3 2.7 54.8 45.2 -52.5 121.7 .sup.a)EP-DVB-A: E:
52.2 mol %, P: 46.5 mol % and divinylbenzene: 1.7 mol %, Mw =
85623, Mn = 39277, PD = 2.18, Tg = -56.5.degree. C.; EP-DVB-B: E:
57.5 mol %, P: 39.4 mol % and divinylbenzene: 3.1 mol %, Mw =
98158, Mn = 41769, PD = 2.35, Tg = -50.7.degree. C.; .sup.b)The
polymer was first extracted by pentane for 24 hrs, and the
insoluble portion was further extracted by xylene; .sup.c)n.d.: not
determined.
EXAMPLES 89-92
Graft Copolymers of Poly(ethylene-ter-propylene-ter-divinylbenzene)
and Polypropylene Prepared by Transition Metal Coordination
Polymerization
[0091] In a 450 ml Parr autoclave equipped with a mechanical
stirrer and N.sub.2 atmosphere, 2.6 g of EP-DVB terpolymer (52.1
mol % ethylene, 43.7 mol % propylene, and 4.2 mole % of DVB;
Tg=-48.7.degree. C.; Mw=68,500 and Mn=34,200 g/mol) was dissolved
in 100 ml toluene. After adding MAO to the polymer solution, the
sealed reactor was then saturated with 20 psi propylene pressure
with or without hydrogen (shown in Table 15). After increasing the
solution temperature to 50.degree. C.,
rac-Me.sub.2Si(2-Me-4-Phenylindenyl)ZrCl.sub.2 (1.25 umol;
[MAO]/[Ti]=1500) catalyst in toluene was then added to the reactor
to initiate the polymerization. Additional propylene and hydrogen
were fed continuously into the reactor by maintaining the constant
pressure during the whole course of the polymerization. After 1
hour, 10 ml of isopropanol was added to terminate the graft-onto
reaction. The precipitated polymer was filtered and then subjected
to a consecutive Soxlet fractionation using pentane and xylene
solvents. Table 15 summarizes the experimental conditions and
results. The polymer structure and composition were determined by
.sup.1H NMR, high temperature GPC and DSC studies. There was no
insoluble fraction. The catalyst activity and incorporation of
propylene to graft copolymer were very dependant on the hydrogen
pressure. A high concentration of isotactic polypropylene can be
incorporated into EP-DVB terpolymer.
15TABLE 15 Synthesis of Poly(ethylene-ter-propylene-
-ter-divinylbenzene)-g-PP graft copolymers by
rac-Me.sub.2Si(2-Me-4-Phenylindenyl)ZrCl.sub.2/MAO catalyst Graft
polym. Cond. Solvent fractionation.sup.b) EP- Wt % Graft
composition Propene DVB.sup.a) H.sub.2 Yield Activity Pentane
Xylene wt % Tg Tm Ex. Psi g psi g kgPP/molZr.hr soluble Soluble
Insoluble EP-DVB PP .degree. C. .degree. C. 89 20 2.6 0 2.5 0 100 0
0 -- -- -- -- 90 20 2.6 2 4.9 1864 29.4 70.6 0 32.3 67.7 -47.3
152.0 91 20 2.6 6 6.56 3184 13.0 87.0 0 30.5 69.5 -47.1 151.4 92 20
2.6 12 7.79 4128 7.9 92.1 0 28.5 71.5 -46.5 151.5 .sup.a)EP-DVB: E:
52.1 mol %, P: 43.7 mol % and divinylbenzene: 4.2 mol %, Mw =
68524, Mn = 34178, PD = 2.09, Tg = -48.7.degree. C.; .sup.b)The
polymer was first extracted by pentane for 24 hrs, and the
insoluble portion was further extracted by xylene.
EXAMPLE 93
Graft Copolymers of Poly(ethylene-ter-propylene-ter-divinylbenzene)
And Polystyrene Prepared by Free Radical Polymerization
[0092] In a 250 ml flask equipped with a stirrer and N.sub.2
atmosphere, 3.1 g of EP-DVB terpolymer (50.1 mol % ethylene, 47.0
mol % propylene, and 2.9 mole % of DVB) was dissolved in 100 ml
benzene. After adding 4.5 g of styrene monomer and 0.25 g of
benzoyl peroxide (BPO) free radical initiator to the polymer
solution, the homogeneous solution was then heated step-wise, to
50.degree. C. for 3 hours, 75.degree. C. for 2 hours and 80.degree.
C. for 3 hours, to initiate the free radical graft-onto reaction.
The reaction was terminated by adding 50 ml of isopropanol. The
precipitated polymer was filtered and then subjected to
fractionation by hexane. The ungrafted EP-DVB polymer was found to
be 0.28 g. About 7.01 g of graft copolymer, with 42 wt % EP-DVB
backbone and 58 wt % polystyrene side chains, was obtained, based
on .sup.1H NMR analysis.
EXAMPLE 94
Graft Copolymer of Poly(ethylene-ter-propylene-ter-divinylbenzene)
and Poly(methylmethacrylate) Prepared by Free Radical
Polymerization
[0093] In a 250 ml flask equipped with a stirrer and N.sub.2
atmosphere, 2.9 g of EP-DVB terpolymer (50.1 mol % ethylene, 47.0
mol % propylene, and 2.9 mole % of DVB) was dissolved in 100 ml
benzene. After adding 5.4 methylmethacrylate monomer and 0.25 g of
benzoyl peroxide (BPO) free radical initiator to the polymer
solution, the homogeneous solution was then heated to initiate the
free radical graft-onto reaction, at 50.degree. C. for 3 hours,
75.degree. C. for 2 hours and 80.degree. C. for 3 hours. Adding 50
ml of isopropanol terminated the reaction. The precipitated polymer
was filtered and then subjected to fractionation by hexane. Only
0.2 g of hexane-soluble ungrafted EP-DVB polymer fraction was
observed. About 7.6 g of graft copolymer, with 36.5 wt % EP-DVB
backbone and 63.5 wt % poly(methylmethacrylate) side chains, was
obtained, based on .sup.1H NMR analysis.
EXAMPLE 95
Graft Copolymer of Poly(ethylene-co-divinylbenzene) and Polystyrene
Prepared by Free Radical Polymerization
[0094] In a 250 ml flask equipped with a stirrer and N.sub.2
atmosphere, 3 g of poly(ethylene-co-divinylbenzene) containing 1.73
mole % of DVB was dissolved in 200 g biphenyl solvent at
125.degree. C. After adding 4.5 g of styrene monomer, 0.3 g of
dicumyl peroxide (DCP) free radical initiator was introduced into
the reactor to initiate the free radical graft-onto reaction. The
reaction was taken place between 125-130.degree. C. for 5 hours
before being terminated by adding 50 ml of isopropanol. The
precipitated polymer was filtered and washed repeatedly with
isopropanol, then dried in vacuum oven to obtain 6.8 g polymer. The
resulting polymer was fractionated by THF into 2.5 g THF-soluble
ungrafted polystyrene and 4.3 g PE-g-PS graft copolymer containing
60 wt % polyethylene and 40 wt % polystyrene, based .sup.1H NMR
analysis.
EXAMPLE 96
Graft Copolymer of Poly(propylene-co-divinylbenzene) Polystyrene
Prepared by Free Radical Polymerization
[0095] In a 250 ml flask equipped with a stirrer and N.sub.2
atmosphere, 3 g of poly(propylene-co-divinylbenzene) containing
0.94 mole % of DVB was dissolved in 200 g biphenyl solvent at
130.degree. C. After adding 4.5 g of styrene monomer, 0.3 g of
dicumyl peroxide (DCP) free radical initiator was introduced into
the reactor to initiate the free radical graft-onto reaction. The
reaction was continued at 130.degree. C. for 5 hours before being
terminated by adding 50 ml of isopropanol. The precipitated polymer
was filtered and washed repeatedly with isopropanol, then dried in
vacuum oven to obtain 6.9 g polymer. The resulting polymer was
fractionated by THF into 3.2 g THF-soluble ungrafted polystyrene
and 3.7 g PP-g-PS graft copolymer containing 70 wt % PP and 30 wt %
PS, based .sup.1H NMR analysis.
EXAMPLE 97
Preparation of Pure 1,4-Divinylbenzene
[0096] Pure 1,4-divinylbenzene (1,4-DVB) monomer was isolated from
commercially available divinylbenzene mixture (Aldrich Chemical
Co.), containing about 60 wt. % divinylbenzene and having a mole
ratio between the 1,3- and 1,4-isomer of about 1 to 2.5, by a
bromination-debromination method. In a 1 L flask equipped with a
magnetic stirring bar, 230 ml of the commercial divinylbenzene
mixture was mixed with 500 ml of benzene. Under stirring and
cooling at 0.degree. C., 120 ml of bromine was dropwised into the
mixed solution for a period of 6 hours. During the bromine
addition, the color of solution changed from deep red through brown
yellow to light yellow. At the last stage, the tetrabromided
1,4-divinylbenzene was crystallized and the solution became gray
white. The crystals were filtered and washed with methanol until
complete decoloration. The resulting crystals were recrystallized
twice from chloroform, filtered and dried. About 95 g of the
tetrabromided 1,4-divinylbenzene, i.e.
1,4-bis(1,2-dibromoethyl)benzene, was obtained. The crystals were
analyzed by DSC and NMR. DSC showed a melting point at 163.degree.
C. .sup.1H NMR spectra showed the expected chemical shifts: 6=7.45
(singlet, 4H, C.sub.6H.sub.4), 5.15 (multiplet, 2H,
CHBrCH.sub.2Br), and 4.10 (multiplet, 4H, CHBrCH.sub.2Br).
[0097] The 1,4-bis(1,2-dibromoethyl)benzene thus obtained was then
subjected to a debromination process. The debromination was carried
out by dissolving 85 g 1,4-bis(1,2-dibromoethyl)benzene crystals
and 0.8 g of p-methoxyphenol in 400 ml of dioxane and 40 ml of
water at elavated temperature. About 30 g of zinc dust were then
added at a rate sufficient to keep the reaction mixture boiling
(.about.95.degree. C.). After the addition was completed, the
reaction was held at 95.degree. C. for another 10 minutes. The
reaction mixture was then cooled to room temperature with an ice
bath. After filtration to remove excess zinc, about 500 ml of ether
was added to the filtrate. The filtrate was then washed with 300 ml
of water several times to completely remove zinc bromide and
dioxane. The organic layer was dried over anhydrous sodium sulfate
and ether was removed by evaporation. The residue,
1,4-divinylbenzene, was further purified by sublimation under
reduced pressure at room temperature. The total yield was
.about.80%. .sup.1H NMR spectra showed the product to be pure
1,4-divinylbenzene with the expected chemical shifts:
(C.sub.2D.sub.2Cl.sub.4, 25.degree. C.): .delta.=7.37 (singlet, 4H,
C.sub.6H.sub.4), 6.70 (quadruplet, 2H, CH.dbd.CH.sub.2), 5.75 and
5.24 (doublet, 2H, CH.dbd.CH.sub.2).
EXAMPLES 98-114
Synthesis of Poly(ethylene-co-divinylbenzene) Copolymers by
Metallocene Catalysts Using Pure 1,4-Divinylbenzene
[0098] A series of copolymerization reactions between ethylene and
pure 1,4-divinylbenzene (obtained from Example 97) were carried out
in a Parr 450 ml stainless autoclave equipped with a mechanical
stirrer. After mixing the quantities of 1,4-divinylbenzene, MAO and
toluene indicated in Table 16, the autoclave was then saturated
with ethylene gas at 50.degree. C. and maintained under ethylene
pressure. The indicated catalyst (2.5 .mu.mol) in toluene was then
added to the autoclave to initiate the polymerization. Additional
ethylene was fed continuously into the autoclave to maintain a
constant ethylene pressure of 20 psi during the course of each
polymerization reaction. After 30 minutes reaction time, each
copolymerization reaction was terminated by adding 100 ml of dilute
HCl solution in MeOH. The resulting polymers were isolated by
filtering, were washed completely with MeOH and were dried under
vacuum for 8 hrs. The amounts of the various reactants and the
results obtained for the series of reactions are set forth in Table
16. The use of rac-Et(Ind).sub.2ZrCl.sub.2/MAO catalyst resulted in
very effective incorporation of 1,4-divinylbenzene to form
completely soluble poly(ethylene-co-1,4-divinylbenzene) copolymers.
.sup.1H NMR spectrum of the copolymers showed three sharp olefinic
proton peaks at 5.2 and 5.7 ppm (doublet, CH.dbd.CH.sub.2) and 6.70
ppm (quadruplet, CH.dbd.CH.sub.2), and aromatic proton peaks at 7.1
and 7.4 ppm (C.sub.6H.sub.4), and the peak intensity ratios
indicated that the mole ratios of TUS/DOU were about 1/1. On the
other hand, the use of non-bridgeted Cp.sub.2ZrCl.sub.2 and
(Ind).sub.2ZrCl.sub.2 catalysts were not effective for the
incorporation of 1,4-divinylbenzene into polyethylene. The use of
[C.sub.5Me.sub.4(SiMe.sub.2N.sup.tBu)]TiCl.sub.2- /MAO catalyst
(having a large opening active site) produced insoluble copolymers,
which indicated that a certain degree of crosslinking took place
during the polymerization.
16TABLE 16 A summary of the copolymerization of ethylene and
1,4-divinylbenzene catalyzed by several metallocene catalysts
Polymerization conditions.sup.a) 1,4-DVB Product Ethylene 1,4-DVB
Yield in polymer in Ex. Catalyst psi mol/l g A.sup.b) mol %
solution 98 Cp.sub.2ZrCl.sub.2 20 0.492 2.35 1880 0.58 Soluble 99
Cp.sub.2ZrCl.sub.2 20 1.770 0.53 424 1.11 Soluble 100
(Ind).sub.2ZrCl.sub.2 20 0.492 2.47 1976 0.63 Soluble 101
(Ind).sub.2ZrCl.sub.2 20 1.770 0.54 408 1.23 Soluble 102
Et(Ind).sub.2ZrCl.sub.2.sup.c 20 0 2.38 1904 0 Soluble 103
Et(Ind).sub.2ZrCl.sub.2 20 0.295 4.52 3616 1.48 Soluble 104
Et(Ind).sub.2ZrCl.sub.2 20 0.492 5.02 4016 2.30 Soluble 105
Et(Ind).sub.2ZrCl.sub.2 20 0.787 5.58 4464 3.28 Soluble 106
Et(Ind).sub.2ZrCl.sub.2 20 1.770 5.06 4048 7.18 Soluble 107
Et(H.sub.4Ind).sub.2ZrCl.sub.2 20 0.492 2.92 2336 1.43 Soluble 108
Et(H.sub.4Ind).sub.2ZrCl.sub.2 20 0.787 2.32 1856 2.01 Soluble 109
Et(H.sub.4Ind).sub.2ZrCl.sub.2 20 1.770 0.77 616 4.01 Soluble 110
Me.sub.2Si(Ind).sub.2ZrCl.sub.2 20 0.0707 4.56 3648 0.78 Soluble
111 Me.sub.2Si(Ind).sub.2ZrCl.sub.2 20 0.295 4.12 3296 -- Insoluble
112 Me.sub.2Si(Ind).sub.2ZrCl.sub.2 20 0.492 5.35 4280 -- Insoluble
113 [(C.sub.5Me.sub.4)SiMe.sub.2N 20 0.0707 1.78 1424 -- Insoluble
(t-Bu)]TiCl.sub.2 114 [(C.sub.5Me.sub.4)SiMe.sub.2N 20 0.295 3.23
2584 -- Insoluble (t-Bu)]TiCl.sub.2 .sup.aOther conditions: 100 ml
toluene as solvent, MAO as cocatalyst. [cat] = 2.5 .times.
10.sup.-6 M, [MAO]/[cat] = 1500, 50.degree. C., 30 minutes.
.sup.bCatalyst activity: kg of polymer per mol of catalyst per hour
.sup.cRac-Et(Ind).sub.2ZrCl.sub.2
EXAMPLES 115-118
Synthesis of Poly(ethylene-co-divinylbenzene) by
Et(Ind).sub.2ZrCl.sub.2/M- AO Catalyst Using a Mixture of 1,3 and
1,4-Divinylbenzene
[0099] In a series of copolymerization reactions, a mixture of 1,3
and 1,4-divinylbenzene (with mole ratio of 1:2.5) was used as the
comonomers in an ethylene polymerization. For each reaction, a
batch slurry polymerization was carried out in a Parr 450 ml
stainless autoclave equipped with a mechanical stirrer. After
mixing the indicated quantities of divinylbenzene, MAO and hexane
in an autoclave, the autoclave was then saturated with ethylene gas
at 50.degree. C. and maintained under ethylene pressure. A
rac-Et(Ind).sub.2ZrCl.sub.2 (2.5 .mu.mol) catalyst in toluene was
added to initiate the polymerization. Additional ethylene was fed
continuously into the autoclave to maintain a constant ethylene
pressure of 20 psi during the entire course of each polymerization
reaction. After reacting at 50.degree. C. for 30 minutes, each
copolymerization reaction was terminated by adding 100 ml of dilute
HCl solution in MeOH. The resulting polymers were isolated by
filtering, were washed completely with MeOH, and were dried under
vacuum for 8 hrs. The amounts of the reactants and the results
obtained are set forth in Table 17.
17TABLE 17 A summary of the copolymerization of ethylene and a
mixture of 1,3- and 1,4-divinylbenzene Polymerization
conditions.sup.a DVB DVB in Ethylene Mixture Yield polymer Product
Ex. Catalsyt psi mol/l g A.sup.b) mol % performance 115
Et(Ind).sub.2ZrCl.sub.2.sup- .c 20 0.295 4.35 3480 1.23 Soluble 116
Et(Ind).sub.2ZrCl.sub.2 20 0.492 4.11 3257 2.01 Soluble 117
Et(Ind).sub.2ZrCl.sub.2 20 0.787 4.15 3320 2.76 Soluble 118
Et(Ind).sub.2ZrCl.sub.2 20 1.292 4.32 3456 4.27 Soluble .sup.aOther
conditions: 100 ml toluene as solvent, MAO as cocatalyst. [cat] =
2.5 .times. 10.sup.-6 M, [MAO]/[cat] = 1500, 50.degree. C., 30
minutes. .sup.bActivity: kg of polymer per mol of catalyst per
hour; .sup.cRac-Et(Ind).sub.2Z- rCl.sub.2
[0100] All of the ethylene/divinylbenzene copolymers were found to
be completely soluble in xylene at elevated temperatures. The
copolymers were analyzed by .sup.1H NMR and gel permeation
chromatography (GPC). GPC results indicated that the copolymers had
a high molecular weight and a narrow molecular weight distribution.
.sup.1H NMR spectra showed that both 1,3 and 1,4-divinylbenzene
were incorporated into in each copolymer with multiple olefinic
proton chemical shifts (around 5.3, 5.7, and 6.8 ppm) and a broad
aromatic proton chemical shift (between 7.0 and 7.4 ppm). It is
very difficult to estimate the mole ratio between the incorporated
1,3 and 1,4-divinylbenzene units. The integrated peak intensity
ratio between olefinic and aromatic protons indicates the mole
ratios of TUS/DOU near 1/1.
EXAMPLE 119-122
Synthesis of Poly(ethylene-ter-1-octene-ter-divinylbenzene) by
rac-Et(Ind).sub.2ZrCl.sub.2/MAO Catalyst Using a Mixture of 1,3 and
1,4-Divinylbenzene
[0101] In a series of terpolymerization reactions, the indicated
quantity (shown in Table 18) of a mixture of 1,3 and
1,4-divinylbenzene (with mole ratio of 1:2.5) was mixed with
1-octene (10 ml) and hexane (100 ml) in a Parr 450 mL stainless
autoclave equipped with a mechanical stirrer. About 3 ml of
methylaluminoxane (MAO) (2.5 M in toluene) was then introduced into
each mixture. The sealed reactor was then saturated with 10 psi
ethylene gas at 50.degree. C. before adding a solution of
rac-Et(Ind).sub.2ZrCl.sub.2 catalyst (2.5 .mu.mol) in toluene to
initiate the polymerization. Additional ethylene was fed
continuously into the reactor by maintaining a constant pressure
(10 psi) during the whole course of the polymerization. After 30
minutes, each reaction was terminated by adding 100 mL of dilute
HCl solution in MeOH. The terpolymer resulting from each reaction
was precipitated in methanol and isolated by filtering. Further
purification was carried out by redissolving the terpolymer in
hexane and then reprecipitating the terpolymer twice in methanol.
All of the terpolymers were found to be completely soluble in
common organic solvents, such as hexane, toluene and
tetrahydrofuran (THF). The terpolymer products were analyzed by
.sup.1H NMR, DSC, and GPC. As summarized in Table 18, all of the
terpolymerization reactions of ethylene/1-octene/divinylbenzene
were very effective when using rac-Et(Ind).sub.2ZrCl.sub.2/MAO
catalyst. A broad composition range of terpolymers was obtained.
The terpolymers were characterized by a high molecular weight and a
narrow molecular weight distribution (Mw/Mn<2.5). In general,
the terpolymer products exhibited a mole ratio of TUS/DOU near
unity and a low Tg<-40.degree. C. in a wide range of copolymer
compositions.
18TABLE 18 A summary of terpolymerization reactions between
ethylene, 1-octene, and a mixture of 1,3- and 1,4-divinylbenzene
ssing rac-Et(Ind).sub.2ZrCl.sub.2/MAO catalyst Polymerization
Polymer conditions.sup.a) Composition [E] [O] [D].sup.c)
Cat..sup.b) [E] [O] [D] Mw Example psi ml ml Activity mol % mol %
mol % g/mol Mw/Mn 119 10 10 2.5 3156 72.2 26.1 1.7 89,400 2.2 120
10 10 5.0 2436 67.5 28.9 3.6 86,700 2.4 121 20 10 2.5 5624 86.7
12.5 0.8 132,000 2.1 122 20 10 5.0 3254 85.9 12.8 1.3 125,600 2.3
.sup.aOther conditions: [cat] = 2.5 .times. 10.sup.-6 M,
[MAO]/[cat] = 3000; solvent: 100 ml hexane; temperature: 50.degree.
C.; time: 30 minutes. .sup.bCatalyst activity: kg of polymer per
mol of catalyst per hour. .sup.c[E]: ethylene; [O]: 1-octene; [D]:
1,3 and 1,4-divinylbenzene mixture
* * * * *